In an adult patient, a Glasgow Coma Scale (GCS) score of 13 or lower necessitates an urgent CT scan of the head. The GCS is a neurological assessment tool that evaluates a patient’s level of consciousness and neurological functioning. It consists of three components: eye opening, verbal response, and motor response. Each component is assigned a score ranging from 1 to 4 or 5, with a higher score indicating a higher level of consciousness.

A GCS score of 15 is considered normal and indicates that the patient is fully conscious. A score of 14 or 13 suggests a mild impairment in consciousness, but it may not necessarily require an urgent CT scan unless there are other concerning symptoms or signs. However, a GCS score of 11 or 9 indicates a moderate to severe impairment in consciousness, which raises concerns for a potentially serious head injury. In these cases, an urgent CT scan of the head is necessary to assess for any structural brain abnormalities or bleeding that may require immediate intervention.

Therefore, in this case, the minimum GCS score that necessitates an urgent CT scan of the head is 13.

Further Reading:

Indications for CT Scanning in Head Injuries (Adults):
– CT head scan should be performed within 1 hour if any of the following features are present:
– GCS < 13 on initial assessment in the ED
– GCS < 15 at 2 hours after the injury on assessment in the ED
– Suspected open or depressed skull fracture
– Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
– Post-traumatic seizure
– New focal neurological deficit
– > 1 episode of vomiting

Indications for CT Scanning in Head Injuries (Children):
– CT head scan should be performed within 1 hour if any of the features in List 1 are present:
– Suspicion of non-accidental injury
– Post-traumatic seizure but no history of epilepsy
– GCS < 14 on initial assessment in the ED for children more than 1 year of age
– Paediatric GCS < 15 on initial assessment in the ED for children under 1 year of age
– At 2 hours after the injury, GCS < 15
– Suspected open or depressed skull fracture or tense fontanelle
– Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
– New focal neurological deficit
– For children under 1 year, presence of bruise, swelling or laceration of more than 5 cm on the head

– CT head scan should be performed within 1 hour if none of the above features are present but two or more of the features in List 2 are present:
– Loss of consciousness lasting more than 5 minutes (witnessed)
– Abnormal drowsiness
– Three or more discrete episodes of vomiting
– Dangerous mechanism of injury (high-speed road traffic accident, fall from a height of

The probable underlying reason for the patient’s symptoms is central pontine myelinolysis. This condition is characterized by the destruction of the myelin sheath in the pons, a region of the brainstem. It is often caused by a rapid correction of hyponatremia, which is a low level of sodium in the blood. In this case, the patient’s serum sodium level was initially low at 117 mmol/L, and the administration of intravenous 3% sodium chloride solution caused a rapid increase in sodium levels. This sudden change in sodium concentration can lead to the development of central pontine myelinolysis. The initial improvement in the patient’s symptoms may have been due to the correction of hyponatremia, but the subsequent development of lethargy and dysarthria suggests the onset of central pontine myelinolysis.

Further Reading:

Syndrome of inappropriate antidiuretic hormone (SIADH) is a condition characterized by low sodium levels in the blood due to excessive secretion of antidiuretic hormone (ADH). ADH, also known as arginine vasopressin (AVP), is responsible for promoting water and sodium reabsorption in the body. SIADH occurs when there is impaired free water excretion, leading to euvolemic (normal fluid volume) hypotonic hyponatremia.

There are various causes of SIADH, including malignancies such as small cell lung cancer, stomach cancer, and prostate cancer, as well as neurological conditions like stroke, subarachnoid hemorrhage, and meningitis. Infections such as tuberculosis and pneumonia, as well as certain medications like thiazide diuretics and selective serotonin reuptake inhibitors (SSRIs), can also contribute to SIADH.

The diagnostic features of SIADH include low plasma osmolality, inappropriately elevated urine osmolality, urinary sodium levels above 30 mmol/L, and euvolemic. Symptoms of hyponatremia, which is a common consequence of SIADH, include nausea, vomiting, headache, confusion, lethargy, muscle weakness, seizures, and coma.

Management of SIADH involves correcting hyponatremia slowly to avoid complications such as central pontine myelinolysis. The underlying cause of SIADH should be treated if possible, such as discontinuing causative medications. Fluid restriction is typically recommended, with a daily limit of around 1000 ml for adults. In severe cases with neurological symptoms, intravenous hypertonic saline may be used. Medications like demeclocycline, which blocks ADH receptors, or ADH receptor antagonists like tolvaptan may also be considered.

It is important to monitor serum sodium levels closely during treatment, especially if using hypertonic saline, to prevent rapid correction that can lead to central pontine myelinolysis. Osmolality abnormalities can help determine the underlying cause of hyponatremia, with increased urine osmolality indicating dehydration or renal disease, and decreased urine osmolality suggesting SIADH or overhydration.

The current algorithm for the treatment of a convulsing child, known as APLS, is as follows:

Step 1 (5 minutes after the start of convulsion):
If a child has been convulsing for 5 minutes or more, the initial dose of benzodiazepine should be administered. This can be done by giving Lorazepam at a dose of 0.1 mg/kg intravenously (IV) or intraosseously (IO) if vascular access is available. Alternatively, buccal midazolam at a dose of 0.5 mg/kg or rectal diazepam at a dose of 0.5 mg/kg can be given if vascular access is not available.

Step 2 (10 minutes after the start of Step 1):
If the convulsion continues for a further 10 minutes, a second dose of benzodiazepine should be given. It is also important to summon senior help at this point.

Step 3 (10 minutes after the start of Step 2):
At this stage, it is necessary to involve senior help to reassess the child and provide guidance on further management. The recommended approach is as follows:
– If the child is not already on phenytoin, a phenytoin infusion should be initiated. This involves administering 20 mg/kg of phenytoin intravenously over a period of 20 minutes.
– If the child is already taking phenytoin, phenobarbitone can be used as an alternative. The recommended dose is 20 mg/kg administered intravenously over 20 minutes.
– In the meantime, rectal paraldehyde can be considered at a dose of 0.8 ml/kg of the 50:50 mixture while preparing the infusion.

Step 4 (20 minutes after the start of Step 3):
If the child is still experiencing convulsions at this stage, it is crucial to have an anaesthetist present. A rapid sequence induction with thiopental is recommended for further management.

Please note that this algorithm is subject to change based on individual patient circumstances and the guidance of medical professionals.

Wernicke’s encephalopathy is a condition that is commonly associated with alcohol abuse and other causes of thiamine deficiency. It is characterized by a triad of symptoms, including acute confusion, ophthalmoplegia (paralysis or weakness of the eye muscles), and ataxia (loss of coordination). Additional features may include papilloedema (swelling of the optic disc), hearing loss, apathy, dysphagia (difficulty swallowing), memory impairment, and hypothermia. Most cases also involve peripheral neuropathy, which typically affects the legs.

The condition is caused by capillary hemorrhages, astrocytosis (abnormal increase in astrocytes, a type of brain cell), and neuronal death in the upper brainstem and diencephalon. These changes can be visualized using MRI scanning, although CT scanning is not very useful for diagnosis.

If left untreated, most patients with Wernicke’s encephalopathy will develop Korsakoff psychosis. This condition is characterized by retrograde amnesia (loss of memory for events that occurred before the onset of amnesia), an inability to form new memories, disordered time perception, and confabulation (fabrication of false memories).

Patients suspected of having Wernicke’s encephalopathy should receive parenteral thiamine (such as Pabrinex) for at least 5 days. Oral thiamine should be administered after the parenteral therapy.

It is important to note that in patients with chronic thiamine deficiency, the infusion of glucose-containing intravenous fluids without thiamine can trigger the development of Wernicke’s encephalopathy.

Erb’s palsy, also known as Erb-Duchenne palsy, is a condition where the arm becomes paralyzed due to an injury to the upper roots of the brachial plexus. The primary root affected is usually C5, although C6 may also be involved in some cases. The main cause of Erb’s palsy is when the arm experiences excessive force during a difficult childbirth, but it can also occur in adults as a result of shoulder trauma.

Clinically, the affected arm will hang by the side with the elbow extended and the forearm turned inward (known as the waiter’s tip sign). Upon examination, there will be a loss of certain movements:

– Shoulder abduction (involving the deltoid and supraspinatus muscles)
– Shoulder external rotation (infraspinatus muscle)
– Elbow flexion (biceps and brachialis muscles)

It is important to differentiate Erb’s palsy from Klumpke’s palsy, which affects the lower roots of the brachial plexus (C8 and T1). Klumpke’s palsy presents with a claw hand due to paralysis of the intrinsic hand muscles, along with sensory loss along the ulnar side of the forearm and hand. If T1 is affected, there may also be the presence of Horner’s syndrome.

NICE has emphasized that certain symptoms and signs can indicate specific diseases as the underlying cause of a fever. In the case of meningococcal disease, the presence of a rash that does not fade when pressed upon (non-blanching rash) is particularly suggestive, especially if the child appears unwell, the lesions are larger than 2 mm in diameter (purpura), the capillary refill time is 3 seconds or longer, or there is neck stiffness. For more information, you can refer to the NICE guidelines on the assessment and initial management of fever in children under 5, as well as the NICE Clinical Knowledge Summary on the management of feverish children.

The symptoms and signs of strokes can vary depending on which blood vessel is affected. Here is a summary of the main symptoms based on the territory affected:

Anterior cerebral artery: This can cause weakness on the opposite side of the body, with the leg and shoulder being more affected than the arm, hand, and face. There may also be minimal loss of sensation on the opposite side of the body. Other symptoms can include difficulty speaking (dysarthria), language problems (aphasia), apraxia (difficulty with limb movements), urinary incontinence, and changes in behavior and personality.

Middle cerebral artery: This can lead to weakness on the opposite side of the body, with the face and arm being more affected than the leg. There may also be a loss of sensation on the opposite side of the body. Depending on the dominant hemisphere of the brain, there may be difficulties with expressive or receptive language (dysphasia). In the non-dominant hemisphere, there may be neglect of the opposite side of the body.

Posterior cerebral artery: This can cause a loss of vision on the opposite side of both eyes (homonymous hemianopia). There may also be defects in a specific quadrant of the visual field. In some cases, there may be a syndrome affecting the thalamus on the opposite side of the body.

It’s important to note that these are just general summaries and individual cases may vary. If you suspect a stroke, it’s crucial to seek immediate medical attention.

Patients with Parkinson’s disease (PD) typically exhibit the following clinical features:

– Hypokinesia (reduced movement)
– Bradykinesia (slow movement)
– Rest tremor (usually occurring at a rate of 4-6 cycles per second)
– Rigidity (increased muscle tone and ‘cogwheel rigidity’)

Other commonly observed clinical features include:

– Gait disturbance (characterized by a shuffling gait and loss of arm swing)
– Loss of facial expression
– Monotonous, slurred speech
– Micrographia (small, cramped handwriting)
– Increased salivation and dribbling
– Difficulty with fine movements

Initially, these signs are typically seen on one side of the body at the time of diagnosis, but they progressively worsen and may eventually affect both sides. In later stages of the disease, additional clinical features may become evident, including:

– Postural instability
– Cognitive impairment
– Orthostatic hypotension

Although PD primarily affects movement, patients often experience psychiatric issues such as depression and dementia. Autonomic disturbances and pain can also occur, leading to significant disability and reduced quality of life for the affected individual. Additionally, family members and caregivers may also be indirectly affected by the disease.

The normal intracranial pressure (ICP) for an adult lying down is typically between 5 and 15 mmHg.

Further Reading:

Intracranial pressure (ICP) refers to the pressure within the craniospinal compartment, which includes neural tissue, blood, and cerebrospinal fluid (CSF). Normal ICP for a supine adult is 5-15 mmHg. The body maintains ICP within a narrow range through shifts in CSF production and absorption. If ICP rises, it can lead to decreased cerebral perfusion pressure, resulting in cerebral hypoperfusion, ischemia, and potentially brain herniation.

The cranium, which houses the brain, is a closed rigid box in adults and cannot expand. It is made up of 8 bones and contains three main components: brain tissue, cerebral blood, and CSF. Brain tissue accounts for about 80% of the intracranial volume, while CSF and blood each account for about 10%. The Monro-Kellie doctrine states that the sum of intracranial volumes is constant, so an increase in one component must be offset by a decrease in the others.

There are various causes of raised ICP, including hematomas, neoplasms, brain abscesses, edema, CSF circulation disorders, venous sinus obstruction, and accelerated hypertension. Symptoms of raised ICP include headache, vomiting, pupillary changes, reduced cognition and consciousness, neurological signs, abnormal fundoscopy, cranial nerve palsy, hemiparesis, bradycardia, high blood pressure, irregular breathing, focal neurological deficits, seizures, stupor, coma, and death.

Measuring ICP typically requires invasive procedures, such as inserting a sensor through the skull. Management of raised ICP involves a multi-faceted approach, including antipyretics to maintain normothermia, seizure control, positioning the patient with a 30º head up tilt, maintaining normal blood pressure, providing analgesia, using drugs to lower ICP (such as mannitol or saline), and inducing hypocapnoeic vasoconstriction through hyperventilation. If these measures are ineffective, second-line therapies like barbiturate coma, optimised hyperventilation, controlled hypothermia, or decompressive craniectomy may be considered.

Klumpke’s palsy, also known as Dejerine-Klumpke palsy, is a condition where the arm becomes paralyzed due to an injury to the lower roots of the brachial plexus. The most commonly affected root is C8, but T1 can also be involved. The main cause of Klumpke’s palsy is when the arm is pulled forcefully in an outward position during a difficult childbirth. It can also occur in adults with apical lung carcinoma (Pancoast’s syndrome).

Clinically, Klumpke’s palsy is characterized by a deformity known as ‘claw hand’, which is caused by the paralysis of the intrinsic hand muscles. There is also a loss of sensation along the ulnar side of the forearm and hand. In some cases where T1 is affected, a condition called Horner’s syndrome may also be present.

Klumpke’s palsy can be distinguished from Erb’s palsy, which affects the upper roots of the brachial plexus (C5 and sometimes C6). In Erb’s palsy, the arm hangs by the side with the elbow extended and the forearm turned inward (known as the ‘waiter’s tip sign’). Additionally, there is a loss of shoulder abduction, external rotation, and elbow flexion.

The posterior interosseous nerve (PIN) is a motor branch of the radial nerve that is located deep within the body. It emerges above the elbow, between the brachioradialis and brachialis muscles, and then divides into two branches: the superficial radial nerve and the PIN. This division occurs at the lateral epicondyle level. As it travels through the forearm, the PIN passes through the supinator muscle, moving from the front to the back surface. In about 30% of individuals, it also passes through a fibrotendinous structure called the arcade of Frohse, which is located below the supinator muscle. The PIN is responsible for supplying all of the extrinsic wrist extensors, with the exception of the extensor carpi radialis longus muscle.

There are several potential causes of damage to the PIN. Fractures, such as a Monteggia fracture, can lead to injury. Inflammation of the radiocapitellar joint, known as radiocapitellar joint synovitis, can also be a contributing factor. Tumors, such as lipomas, may cause damage as well. Additionally, entrapment of the PIN within the arcade of Frohse can result in a condition known as PIN syndrome.

It is important to note that injury to the PIN can be easily distinguished from injury to the radial nerve in other areas of the arm, such as the spiral groove. This is because there will be no sensory involvement and no wrist drop, as the extensor carpi radialis longus muscle remains unaffected.

The anterior interosseous nerve (AIN) is a branch of the median nerve. It primarily functions as a motor nerve, supplying the flexor pollicis longus muscle, the lateral half of the flexor digitorum profundus muscle, and the pronator quadratus muscle. Damage to the AIN can result in weakness and difficulty moving the index and middle fingers.

The Parkinson-plus syndromes are a group of neurodegenerative disorders that share similar features with Parkinson’s disease but also have additional clinical characteristics that set them apart from idiopathic Parkinson’s disease (iPD). These syndromes include Multiple System Atrophy (MSA), Progressive Supranuclear Palsy (PSP), Corticobasal degeneration (CBD), and Dementia with Lewy Bodies (DLB).

Multiple System Atrophy (MSA) is a less common condition than iPD and PSP. It is characterized by the loss of cells in multiple areas of the nervous system. MSA progresses rapidly, often leading to wheelchair dependence within 3-4 years of diagnosis. Some distinguishing features of MSA include autonomic dysfunction, bladder control problems, erectile dysfunction, blood pressure changes, early-onset balance problems, neck or facial dystonia, and a high-pitched voice.

To summarize the distinguishing features of the Parkinson-plus syndromes compared to iPD, the following table provides a comparison:

iPD:
– Symptom onset: One side of the body affected more than the other
– Tremor: Typically starts at rest on one side of the body
– Levodopa response: Excellent response
– Mental changes: Depression
– Balance/falls: Late in the disease
– Common eye abnormalities: Dry eyes, trouble focusing

MSA:
– Symptom onset: Both sides equally affected
– Tremor: Not common but may occur
– Levodopa response: Minimal response (but often tried in early stages of disease)
– Mental changes: Depression
– Balance/falls: Within 1-3 years
– Common eye abnormalities: Dry eyes, trouble focusing

PSP:
– Symptom onset: Both sides equally affected
– Tremor: Less common, if present affects both sides
– Levodopa response: Minimal response (but often tried in early stages of disease)
– Mental changes: Personality changes, depression
– Balance/falls: Within 1 year
– Common eye abnormalities: Dry eyes, difficulty in looking downwards

CBD:
– Symptom onset: One side of the body affected more than the other
– Tremor: Not common but may occur
– Levodopa response: Minimal response (but often tried in early stages of disease)
– Mental changes: Depression
– Balance/falls: Within 1-3 years
– Common eye abnormalities: Dry eyes, trouble focusing

Patients with Parkinson’s disease (PD) typically exhibit the following clinical features:

– Hypokinesia (reduced movement)
– Bradykinesia (slow movement)
– Rest tremor (usually occurring at a rate of 4-6 cycles per second)
– Rigidity (increased muscle tone and ‘cogwheel rigidity’)

Other commonly observed clinical features include:

– Gait disturbance (characterized by a shuffling gait and loss of arm swing)
– Loss of facial expression
– Monotonous, slurred speech
– Micrographia (small, cramped handwriting)
– Increased salivation and dribbling
– Difficulty with fine movements

Initially, these signs are typically seen on one side of the body at the time of diagnosis, but they progressively worsen and may eventually affect both sides. In later stages of the disease, additional clinical features may become evident, including:

– Postural instability
– Cognitive impairment
– Orthostatic hypotension

Although PD primarily affects movement, patients often experience psychiatric issues such as depression and dementia. Autonomic disturbances and pain can also occur, leading to significant disability and reduced quality of life for the affected individual. Additionally, family members and caregivers may also be indirectly affected by the disease.

Intracranial hemorrhages can be categorized based on their location into epidural, subdural, subarachnoid, or intracerebral hemorrhages. The patient in this case is experiencing a severe headache accompanied by signs of meningismus, which strongly suggests a diagnosis of subarachnoid hemorrhage. Additionally, there is no history of trauma, and most cases of subarachnoid hemorrhage are caused by the rupture of a berry aneurysm located in the circle of Willis. Hypertension is a significant risk factor for the rupture of an aneurysm.

During the patient’s hospital stay, they develop an ischemic stroke, which is confirmed by a CT scan. This is most likely a result of cerebral vasospasm secondary to the subarachnoid hemorrhage. To prevent this complication, patients are often treated with the cerebral selective calcium channel blocker Nimodipine.

Another potential complication of this condition is rebleeding, with the highest risk occurring in the first few days. Rebleeding can be potentially fatal, so it is crucial to repair the aneurysm as soon as possible. The presence of blood in the subarachnoid space can also disrupt the production and drainage of cerebrospinal fluid, leading to hydrocephalus.

Long-term complications of subarachnoid hemorrhage include epilepsy, with most patients experiencing their first seizure within a year after the hemorrhage. However, the risk of epilepsy decreases over time. Cognitive dysfunction is also a common long-term complication and can manifest as memory loss, difficulty concentrating, or challenges in performing regular tasks. Emotional problems, such as depression and anxiety, are frequently observed as well.

The symptoms and signs of strokes can vary depending on which blood vessel is affected. Here is a summary of the main symptoms based on the territory affected:

Anterior cerebral artery: This can cause weakness on the opposite side of the body, with the leg and shoulder being more affected than the arm, hand, and face. There may also be minimal loss of sensation on the opposite side of the body. Other symptoms can include difficulty speaking (dysarthria), language problems (aphasia), apraxia (difficulty with limb movements), urinary incontinence, and changes in behavior and personality.

Middle cerebral artery: This can lead to weakness on the opposite side of the body, with the face and arm being more affected than the leg. There may also be a loss of sensation on the opposite side of the body. Depending on the dominant hemisphere of the brain, there may be difficulties with expressive or receptive language (dysphasia). In the non-dominant hemisphere, there may be neglect of the opposite side of the body.

Posterior cerebral artery: This can cause a loss of vision on the opposite side of both eyes (homonymous hemianopia). There may also be defects in a specific quadrant of the visual field. In some cases, there may be a syndrome affecting the thalamus on the opposite side of the body.

It’s important to note that these are just general summaries and individual cases may vary. If you suspect a stroke, it’s crucial to seek immediate medical attention.

Due to the potentially life-threatening nature of the disease, it is crucial to initiate treatment without waiting for laboratory confirmation. Immediate administration of antibiotics is necessary.

In a hospital setting, the preferred agents for treatment are IV ceftriaxone (2 g for adults; 80 mg/kg for children) or IV cefotaxime (2 g for adults; 80 mg/kg for children). In the prehospital setting, IM benzylpenicillin can be given as an alternative. If there is a history of anaphylaxis to cephalosporins, chloramphenicol is a suitable alternative.

It is important to prioritize prompt treatment due to the severity of the disease. The recommended antibiotics should be administered as soon as possible to ensure the best possible outcome for the patient.

Parkinson’s disease (PD) is a progressive neurodegenerative condition that occurs when the dopamine-containing cells in the substantia nigra die. It is estimated that PD affects around 100-180 individuals per 100,000 of the population, which translates to approximately 6-11 people per 6,000 individuals in the general population of the UK. The annual incidence of PD is between 4-20 cases per 100,000 people. The prevalence of PD increases with age, with approximately 0.5% of individuals aged 65 to 74 being affected and 1-2% of individuals aged 75 and older. Additionally, PD is more prevalent and has a higher incidence in males.

The classic clinical features of Parkinson’s disease include hypokinesia, which refers to a poverty of movement, and bradykinesia, which is characterized by slowness of movement. Rest tremor, typically occurring at a rate of 4-6 cycles per second, is also commonly observed in PD patients. Another clinical feature is rigidity, which is characterized by increased muscle tone and a phenomenon known as cogwheel rigidity.

Migraine without aura typically needs to meet the specific criteria set by the International Headache Society. These criteria include experiencing at least five attacks that meet the requirements outlined in criteria 2-4. The duration of these headache attacks should last between 4 to 72 hours. Additionally, the headache should exhibit at least two of the following characteristics: unilateral location, pulsating quality, moderate or severe pain intensity, and aggravation or avoidance of routine physical activity. Furthermore, during the headache, individuals should experience at least one of the following symptoms: nausea and/or vomiting, photophobia, and phonophobia. For more detailed information, you can refer to the guidelines provided by The British Association for the Study of Headache.

Obstruction of the long circumferential branches of the basilar artery leads to the lateral pontine syndrome. This condition is characterized by several symptoms. Firstly, there is ataxia, which is caused by damage to the cerebral peduncles. Additionally, there is ipsilateral loss of pain and temperature sense on the face, resulting from damage to CN V. Another symptom is ipsilateral paralysis of the upper and lower face, which occurs due to damage to CN VII. Furthermore, vertigo, nystagmus, tinnitus, deafness, and vomiting are present, all of which are caused by damage to CN VIII. Lastly, there is contralateral sensory loss to the body, which is a result of damage to the spinothalamic tracts.

Haloperidol should not be used in patients with Parkinson’s, Lewy body dementia, or prolonged QT syndrome. It is the first choice for controlling aggressive behavior in most patients with delirium, but lorazepam is preferred for patients with Parkinson’s, Lewy body dementia, prolonged QT syndrome, extrapyramidal side effects, or delirium due to alcohol withdrawal. Haloperidol can reduce the effectiveness of levodopa in Parkinson’s disease by blocking dopamine receptors in the corpus striatum, which can lead to worsened motor function, psychosis, or a combination of both.

Further Reading:

Delirium is an acute syndrome that causes disturbances in consciousness, attention, cognition, and perception. It is also known as an acute confusional state. The DSM-IV criteria for diagnosing delirium include recent onset of fluctuating awareness, impairment of memory and attention, and disorganized thinking. Delirium typically develops over hours to days and may be accompanied by behavioral changes, personality changes, and psychotic features. It often occurs in individuals with predisposing factors, such as advanced age or multiple comorbidities, when exposed to new precipitating factors, such as medications or infection. Symptoms of delirium fluctuate throughout the day, with lucid intervals occurring during the day and worse disturbances at night. Falling and loss of appetite are often warning signs of delirium.

Delirium can be classified into three subtypes based on the person’s symptoms. Hyperactive delirium is characterized by inappropriate behavior, hallucinations, and agitation. Restlessness and wandering are common in this subtype. Hypoactive delirium is characterized by lethargy, reduced concentration, and appetite. The person may appear quiet or withdrawn. Mixed delirium presents with signs and symptoms of both hyperactive and hypoactive subtypes.

The exact pathophysiology of delirium is not fully understood, but it is believed to involve multiple mechanisms, including cholinergic deficiency, dopaminergic excess, and inflammation. The cause of delirium is usually multifactorial, with predisposing factors and precipitating factors playing a role. Predisposing factors include older age, cognitive impairment, frailty, significant injuries, and iatrogenic events. Precipitating factors include infection, metabolic or electrolyte disturbances, cardiovascular disorders, respiratory disorders, neurological disorders, endocrine disorders, urological disorders, gastrointestinal disorders, severe uncontrolled pain, alcohol intoxication or withdrawal, medication use, and psychosocial factors.

Delirium is highly prevalent in hospital settings, affecting up to 50% of inpatients aged over 65 and occurring in 30% of people aged over 65 presenting to the emergency department. Complications of delirium include increased risk of death, high in-hospital mortality rates, higher mortality rates following hospital discharge, increased length of stay in hospital, nosocomial infections, increased risk of admission to long-term care or re-admission to hospital, increased incidence of dementia, increased risk of falls and associated injuries and pressure sores.

Between 60 and 80% of individuals who experience seizures will have their seizure stopped by a single dose of intravenous benzodiazepine. Benzodiazepines have a high solubility in lipids and can quickly pass through the blood-brain barrier. This is why they have a fast onset of action.

As the initial treatment, intravenous lorazepam should be administered. If intravenous lorazepam is not accessible, intravenous diazepam can be used instead. In cases where it is not possible to establish intravenous access promptly, buccal midazolam can be utilized.

Occlusion of branches of the anterior spinal artery leads to the development of the medial medullary syndrome. This condition is characterized by several distinct symptoms. Firstly, there is contralateral hemiplegia, which occurs due to damage to the pyramidal tracts. Additionally, there is contralateral loss of joint position sense, vibratory sense, and discriminatory touch, resulting from damage to the medial lemniscus. Lastly, there is ipsilateral deviation and paralysis of the tongue, which is caused by damage to the hypoglossal nucleus.

A subarachnoid haemorrhage (SAH) occurs when there is spontaneous bleeding into the subarachnoid space and is often a catastrophic event. The incidence of SAH is 9 cases per 100,000 people per year, and it typically affects individuals between the ages of 35 and 65.

Approximately 80% of SAH cases are caused by the rupture of berry (saccular) aneurysms, while 15% are caused by arteriovenous malformations (AVM). In less than 5% of cases, no specific cause can be identified. Berry aneurysms are commonly associated with polycystic kidneys, Ehlers-Danlos Syndrome, and coarctation of the aorta.

There are several risk factors for SAH, including smoking, hypertension, bleeding disorders, alcohol misuse, and mycotic aneurysm. Additionally, a family history of SAH can increase the likelihood of developing the condition.

Patients with SAH typically experience a sudden and severe occipital headache, often described as the worst headache of my life. This may be accompanied by symptoms such as vomiting, collapse, seizures, and coma. Clinical signs of SAH include neck stiffness, a positive Kernig’s sign, and focal neurological abnormalities. Fundoscopy may reveal subhyaloid retinal haemorrhages in approximately 25% of patients.

Re-bleeding occurs in 30-40% of patients who survive the initial episode, with the highest risk occurring between 7 and 14 days after the initial bleed. If left untreated, SAH has a mortality rate of nearly 50% within the first eight weeks following presentation. Prolonged coma is associated with a 100% mortality rate.

The first-line investigation for SAH is a CT head scan, which can detect over 95% of cases if performed within the first 24 hours. The sensitivity of the CT scan increases to nearly 100% if performed within 6 hours of symptom onset. If the CT scan is negative, a lumbar puncture (LP) should be performed to diagnose SAH. The LP should be conducted at least 12 hours after the onset of headache, unless there are contraindications. Approximately 3% of patients with a negative CT scan will be confirmed to have had a SAH following an LP.

Radial nerve injuries often occur in conjunction with fractures of the humerus. The most common cause of a radial nerve palsy is external compression or trauma to the radial nerve as it passes through the spiral groove in the middle of the humerus.

There are several factors that can lead to damage of the radial nerve in the spiral groove. These include trauma, such as a fracture in the middle of the humerus, compression known as Saturday night palsy, and iatrogenic causes like injections.

When the radial nerve is injured within the spiral groove, it results in weakness of the wrist and metacarpophalangeal joints. However, elbow extension is not affected because the branches to the triceps and anconeus muscles originate before the spiral groove. The interphalangeal joints remain unaffected as well, as they are supplied by the median and ulnar nerves. Sensory loss will be experienced over the dorsal aspect of the forearm, extending from below the elbow to the 1st dorsal interosseous.

In contrast, injury to the radial nerve in the axilla will also cause weakness of elbow extension and sensory loss in the distribution of the more proximal cutaneous branches. This helps distinguish it from injury in the spiral groove.

In the forearm, the posterior interosseous branch of the radial nerve can also be damaged. This can occur due to injury to the radial head or entrapment in the supinator muscle under the arcade of Frohse. However, this type of injury can be easily distinguished from injury in the spiral groove because there is no sensory involvement and no wrist drop, thanks to the preservation of the extensor carpi radialis longus. Nonetheless, there will still be weakness in the wrist and fingers.

The most probable diagnosis in this case is idiopathic intracranial hypertension, also known as benign intracranial hypertension or pseudotumour cerebri. This condition typically affects overweight women in their 20s and 30s.

The clinical features of idiopathic intracranial hypertension include:
– Headache: The headache is usually worse in the morning and evenings, relieved by standing, and worsened when lying down. It can also be aggravated by coughing and sneezing. Some patients may experience pain around the shoulder girdle.
– Nausea and vomiting
– Visual field defects: These develop gradually over time.
– 6th nerve palsy and diplopia
– Bilateral papilloedema

To investigate this condition, the patient should undergo a CT scan and/or MRI of the brain, as well as a lumbar puncture to measure the opening pressure and analyze the cerebrospinal fluid (CSF).

The primary treatment goal for idiopathic intracranial hypertension is to prevent visual loss. This can be achieved through one of the following strategies:
– Repeated lumbar puncture to control intracranial pressure (ICP)
– Medical treatment with acetazolamide
– Surgical decompression of the optic nerve sheath

The Parkinson-plus syndromes are a group of neurodegenerative disorders that share similar features with Parkinson’s disease but also have additional clinical characteristics that set them apart from idiopathic Parkinson’s disease (iPD). These syndromes include Multiple System Atrophy (MSA), Progressive Supranuclear Palsy (PSP), Corticobasal degeneration (CBD), and Dementia with Lewy Bodies (DLB).

Multiple System Atrophy (MSA) is a less common condition than iPD and PSP. It is characterized by the loss of cells in multiple areas of the nervous system. MSA progresses rapidly, often leading to wheelchair dependence within 3-4 years of diagnosis. Some distinguishing features of MSA include autonomic dysfunction, bladder control problems, erectile dysfunction, blood pressure changes, early-onset balance problems, neck or facial dystonia, and a high-pitched voice.

To summarize the distinguishing features of the Parkinson-plus syndromes compared to iPD, the following table provides a comparison:

iPD:
– Symptom onset: One side of the body affected more than the other
– Tremor: Typically starts at rest on one side of the body
– Levodopa response: Excellent response
– Mental changes: Depression
– Balance/falls: Late in the disease
– Common eye abnormalities: Dry eyes, trouble focusing

MSA:
– Symptom onset: Both sides equally affected
– Tremor: Not common but may occur
– Levodopa response: Minimal response (but often tried in early stages of disease)
– Mental changes: Depression
– Balance/falls: Within 1-3 years
– Common eye abnormalities: Dry eyes, trouble focusing

PSP:
– Symptom onset: Both sides equally affected
– Tremor: Less common, if present affects both sides
– Levodopa response: Minimal response (but often tried in early stages of disease)
– Mental changes: Personality changes, depression
– Balance/falls: Within 1 year
– Common eye abnormalities: Dry eyes, difficulty in looking downwards

CBD:
– Symptom onset: One side of the body affected more than the other
– Tremor: Not common but may occur
– Levodopa response: Minimal response (but often tried in early stages of disease)
– Mental changes: Depression
– Balance/falls: Within 1-3 years
– Common eye abnormalities: Dry eyes, trouble focusing

The ulnar nerve provides innervation to several muscles in the hand. These include the palmar interossei, dorsal interossei, medial two lumbricals, and abductor digiti minimi. On the other hand, the median nerve innervates the opponens pollicis, lateral two lumbricals, and flexor pollicis brevis. Lastly, the radial nerve is responsible for innervating the extensor digitorum muscle.

Motor Neuron Disease (MND) is a group of degenerative diseases that primarily involve the loss of specific neurons in the motor cortex, cranial nerve nuclei, and anterior horn cells. Both upper and lower motor neurons are affected in this condition. It is important to note that MND does not cause any sensory or sphincter disturbances, and it does not affect eye movements.

MND is relatively uncommon, with a prevalence of approximately 5-7 cases per 100,000 individuals. The median age of onset in the United Kingdom is 60 years, and unfortunately, it often leads to fatality within 2 to 4 years of diagnosis. The treatment for MND mainly focuses on providing supportive care through a multidisciplinary approach.

There are four distinct clinical patterns observed in MND. The first pattern, known as Amyotrophic Lateral Sclerosis (ALS), accounts for up to 50% of MND cases. It involves the loss of motor neurons in both the motor cortex and the anterior horn of the spinal cord. Clinically, individuals with ALS experience weakness and exhibit signs of both upper and lower motor neuron involvement.

The second pattern, called Progressive Bulbar Palsy, occurs in up to 10% of MND cases. This condition specifically affects cranial nerves IX-XII, resulting in Bulbar and pseudobulbar palsy.

Progressive Muscular Atrophy is the third pattern, also seen in up to 10% of MND cases. It primarily affects the anterior horn cells, leading to the presence of only lower motor neuron signs.

Lastly, Primary Lateral Sclerosis involves the loss of Betz cells in the motor cortex. Clinically, individuals with this pattern exhibit upper motor neuron signs, including marked spastic leg weakness and pseudobulbar palsy.

Subdural hematoma (SDH) occurs when the bridging veins in the cortex of the brain tear and cause bleeding in the space between the brain and the outermost protective layer. This is different from extradural hematoma (EDH), which is usually caused by a rupture in the middle meningeal artery.

Further Reading:

A subdural hematoma (SDH) is a condition where there is a collection of blood between the dura mater and the arachnoid mater of the brain. It occurs when the cortical bridging veins tear and bleed into the subdural space. Risk factors for SDH include head trauma, cerebral atrophy, advancing age, alcohol misuse, and certain medications or bleeding disorders. SDH can be classified as acute, subacute, or chronic depending on its age or speed of onset. Acute SDH is typically the result of head trauma and can progress to become chronic if left untreated.

The clinical presentation of SDH can vary depending on the nature of the condition. In acute SDH, patients may initially feel well after a head injury but develop more serious neurological symptoms later on. Chronic SDH may be detected after a CT scan is ordered to investigate confusion or cognitive decline. Symptoms of SDH can include increasing confusion, progressive decline in neurological function, seizures, headache, loss of consciousness, and even death.

Management of SDH involves an ABCDE approach, seizure management, confirming the diagnosis with CT or MRI, checking clotting and correcting coagulation abnormalities, managing raised intracranial pressure, and seeking neurosurgical opinion. Some SDHs may be managed conservatively if they are small, chronic, the patient is not a good surgical candidate, and there are no neurological symptoms. Neurosurgical intervention typically involves a burr hole craniotomy to decompress the hematoma. In severe cases with high intracranial pressure and significant brain swelling, a craniectomy may be performed, where a larger section of the skull is removed and replaced in a separate cranioplasty procedure.

CT imaging can help differentiate between subdural hematoma and other conditions like extradural hematoma. SDH appears as a crescent-shaped lesion on CT scans.

Maintaining adequate blood pressure is crucial in managing increased intracranial pressure (ICP). The recommended blood pressure targets may vary depending on the source. The Scottish Intercollegiate Guidelines Network (SIGN) suggests maintaining an adequate blood pressure, while the 4th edition of the Brain Trauma Foundation recommends maintaining a systolic blood pressure (SBP) above 100 mm Hg for individuals aged 50-69 years (or above 110 mm Hg for those aged 15-49 years) to reduce mortality and improve outcomes.

When managing a patient with increased ICP, the initial steps should include maintaining normal body temperature to prevent fever, positioning the patient with a 30º head-up tilt, and administering analgesia and sedation as needed. It is important to monitor and maintain blood pressure, using inotropes if necessary to achieve the target. Additionally, preparations should be made to use medications such as Mannitol or hypertonic saline to lower ICP if required. Hyperventilation may also be considered, although it carries the risk of inducing ischemia and requires monitoring of carbon dioxide levels.

Further Reading:

Intracranial pressure (ICP) refers to the pressure within the craniospinal compartment, which includes neural tissue, blood, and cerebrospinal fluid (CSF). Normal ICP for a supine adult is 5-15 mmHg. The body maintains ICP within a narrow range through shifts in CSF production and absorption. If ICP rises, it can lead to decreased cerebral perfusion pressure, resulting in cerebral hypoperfusion, ischemia, and potentially brain herniation.

The cranium, which houses the brain, is a closed rigid box in adults and cannot expand. It is made up of 8 bones and contains three main components: brain tissue, cerebral blood, and CSF. Brain tissue accounts for about 80% of the intracranial volume, while CSF and blood each account for about 10%. The Monro-Kellie doctrine states that the sum of intracranial volumes is constant, so an increase in one component must be offset by a decrease in the others.

There are various causes of raised ICP, including hematomas, neoplasms, brain abscesses, edema, CSF circulation disorders, venous sinus obstruction, and accelerated hypertension. Symptoms of raised ICP include headache, vomiting, pupillary changes, reduced cognition and consciousness, neurological signs, abnormal fundoscopy, cranial nerve palsy, hemiparesis, bradycardia, high blood pressure, irregular breathing, focal neurological deficits, seizures, stupor, coma, and death.

Measuring ICP typically requires invasive procedures, such as inserting a sensor through the skull. Management of raised ICP involves a multi-faceted approach, including antipyretics to maintain normothermia, seizure control, positioning the patient with a 30º head up tilt, maintaining normal blood pressure, providing analgesia, using drugs to lower ICP (such as mannitol or saline), and inducing hypocapnoeic vasoconstriction through hyperventilation. If these measures are ineffective, second-line therapies like barbiturate coma, optimised hyperventilation, controlled hypothermia, or decompressive craniectomy may be considered.