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.

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.

Co-beneldopa, such as Madopar®, is a medication that combines levodopa and benserazide, a dopa-decarboxylase inhibitor. Levodopa is a precursor of dopamine and has been the primary treatment for Parkinson’s disease since the 1970s. To minimize the side effects of levodopa, it is administered with a dopa-decarboxylase inhibitor (DDI) to reduce its availability in the peripheral system. However, patients may still experience adverse effects like nausea, dizziness, sleepiness, dyskinesia, mood changes, confusion, hallucinations, and delusions.

None of the other combination medications mentioned in this question cause the listed side effects.

Co-dydramol is a pain reliever that contains dihydrocodeine tartrate and paracetamol.

Co-flumactone is a medication that combines spironolactone, a potassium-sparing diuretic, and hydroflumethiazide, a type of thiazide diuretic used for managing congestive cardiac failure.

Co-tenidone is a combination of atenolol and chlorthalidone, primarily used for treating hypertension.

Co-simalcite, also known as Altacite plus, is an antacid that contains two main ingredients: hydrotalcite and activated dimeticone.

This woman is displaying symptoms and signs that are in line with a diagnosis of meningococcal septicaemia. In the United Kingdom, the majority of cases of meningococcal septicaemia are caused by Neisseria meningitidis group B.

The implementation of a vaccination program for Neisseria meningitidis group C has significantly reduced the prevalence of this particular type. However, a vaccine for group B disease is currently undergoing clinical trials and is not yet accessible for widespread use.

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.

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.

When there is damage to the facial nerve in the LMN, the patient will experience paralysis in the forehead and will be unable to wrinkle their brow. However, in an upper motor neuron lesion, the frontalis muscle is not affected, so the patient can still furrow their brow normally and their ability to close their eyes and blink is not affected. Lower motor neuron lesions affect the final part of the nerve pathway to all branches of the facial nerve, resulting in paralysis of the forehead and the rest of the face on that side. It is important to note that the speed of onset may provide some clues about the cause of the lesion, but it does not help determine the specific location of the damage.

Further Reading:

Bell’s palsy is a condition characterized by sudden weakness or paralysis of the facial nerve, resulting in facial muscle weakness or drooping. The exact cause is unknown, but it is believed to be related to viral infections such as herpes simplex or varicella zoster. It is more common in individuals aged 15-45 years and those with diabetes, obesity, hypertension, or upper respiratory conditions. Pregnancy is also a risk factor.

Diagnosis of Bell’s palsy is typically based on clinical symptoms and ruling out other possible causes of facial weakness. Symptoms include rapid onset of unilateral facial muscle weakness, drooping of the eyebrow and corner of the mouth, loss of the nasolabial fold, otalgia, difficulty chewing or dry mouth, taste disturbance, eye symptoms such as inability to close the eye completely, dry eye, eye pain, and excessive tearing, numbness or tingling of the cheek and mouth, speech articulation problems, and hyperacusis.

When assessing a patient with facial weakness, it is important to consider other possible differentials such as stroke, facial nerve tumors, Lyme disease, granulomatous diseases, Ramsay Hunt syndrome, mastoiditis, and chronic otitis media. Red flags for these conditions include insidious and painful onset, duration of symptoms longer than 3 months with frequent relapses, pre-existing risk factors, systemic illness or fever, vestibular or hearing abnormalities, and other cranial nerve involvement.

Management of Bell’s palsy involves the use of steroids, eye care advice, and reassurance. Steroids, such as prednisolone, are recommended for individuals presenting within 72 hours of symptom onset. Eye care includes the use of lubricating eye drops, eye ointment at night, eye taping if unable to close the eye at night, wearing sunglasses, and avoiding dusty environments. Reassurance is important as the majority of patients make a complete recovery within 3-4 months. However, some individuals may experience sequelae such as facial asymmetry, gustatory lacrimation, inadequate lid closure, brow ptosis, drooling, and hemifacial spasms.

Antiviral treatments are not currently recommended as a standalone treatment for Bell’s palsy, but they may be given in combination with corticosteroids on specialist advice. Referral to an ophthalmologist is necessary if the patient has eye symptoms such as pain, irritation, or itch.

The recommended dosage of buccal midazolam for treating a child experiencing seizures is 0.5 mg per kilogram of body weight.

NICE has emphasized that there are particular symptoms and indications that may indicate specific diseases as the underlying cause of a fever. In the case of herpes simplex encephalitis, the following symptoms and signs may suggest its presence: the presence of a focal neurological sign, focal seizures, and a decreased level of consciousness. For more information on this topic, you may refer to the NICE guidelines on the assessment and initial management of fever in children under the age of 5, as well as the NICE Clinical Knowledge Summary on the management of feverish children.

The median nerve originates from the lateral and medial cords of the brachial plexus and receives contributions from the ventral roots of C5-C7 (lateral cord) and C8 and T1 (medial cord). It serves both motor and sensory functions.

In terms of motor function, the median nerve innervates the flexor muscles in the anterior compartment of the forearm, excluding the flexor carpi ulnaris and a portion of the flexor digitorum profundus, which are instead innervated by the ulnar nerve. Additionally, it innervates the thenar muscles and the lateral two lumbricals.

Regarding sensory function, the median nerve gives rise to the palmar cutaneous branch, which provides innervation to the lateral part of the palm. It also gives rise to the digital cutaneous branch, which innervates the lateral three and a half fingers on the palmar surface of the hand.

Within the forearm, the median nerve branches into two major branches. The first is the anterior interosseous nerve (AIN), which supplies the flexor pollicis longus, pronator quadratus, and the lateral half of the flexor digitorum profundus. The second is the palmar cutaneous branch, which provides sensory innervation to the skin of the radial palm.

Differentiating between damage to the median nerve at the elbow and wrist can be done by considering these two branches. Injury at the elbow affects these branches, while injury at the wrist spares them. It is important to note that the palmar cutaneous branch travels superficially to the flexor retinaculum and therefore remains functional in carpal tunnel syndrome. However, it can be damaged by laceration at the wrist.

A comparison of median nerve lesions at the wrist and elbow is presented below:

Median nerve at elbow:
– Motor loss: Weak wrist flexion and abduction, loss of thumb abduction and opposition, loss of flexion of index and middle fingers
– Sensory loss: Lateral 3 and ½ fingers and nail beds, lateral side of palm
– Hand deformity: Ulnar deviation of wrist, thenar wasting, papal benediction on flexing fingers

Median nerve at wrist:
– Motor loss: Loss of thumb abduction and opposition, wrist and finger flexion intact (due to intact AIN)
– Sensory loss: Lateral 3 and ½ fingers and nail beds, lateral side of palm (but can be preserved depending upon palmar cutaneous branch)
– Hand deformity: Thenar wasting, no ulnar deviation of wrist or papal benediction (due to intact AIN)

Guillain-Barré syndrome (GBS) affects approximately 1-2 individuals per 100,000 annually and is a condition that primarily affects the peripheral nervous system, including the autonomic system. The most common initial symptom is weakness in the hands or feet, often accompanied by pain and tingling sensations as the paralysis spreads. Miller Fisher syndrome, a variant of GBS, is characterized by a triad of symptoms: ataxia, areflexia, and ophthalmoplegia.

Due to the potential serious consequences of autonomic involvement, such as fluctuations in blood pressure and cardiac arrhythmias, patients with GBS are typically hospitalized. As the diaphragm becomes paralyzed and swallowing becomes difficult, patients may require ventilation and nasogastric feeding.

GBS is an autoimmune disease that usually develops within three weeks of an infection. The leading cause is Campylobacter jejuni, followed by Epstein-Barr virus, cytomegalovirus, and Mycoplasma pneumoniae. While the patient’s immune response effectively targets the initial infection, it also mistakenly attacks the host tissue.

Symptoms of GBS typically peak around four weeks and then gradually improve. Diagnosis is based on clinical examination, which confirms the presence of areflexia and progressive weakness in the legs (and sometimes arms). Nerve conduction studies and lumbar puncture can also aid in diagnosis, with the latter often showing elevated protein levels and few white blood cells.

Treatment for GBS is primarily supportive, with the use of immunoglobulins to shorten the duration of the illness being common. Plasma exchange may also be utilized, although it has become less common since the introduction of immunoglobulin therapy.

Approximately 80% of patients with GBS make a full recovery, although this often requires a lengthy hospital stay. The mortality rate is around 5%, depending on the availability of necessary facilities such as ventilatory support during the acute phase. Additionally, about 15% of patients may experience some permanent disability, such as weakness or pain.

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.

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.

On average, the intracranial volume in adults is around 1400ml.

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.

The most probable diagnosis in this case is a subarachnoid haemorrhage (SAH).

When assessing patients who present with an SAH, there may be focal neurological signs that can indicate the potential location of the aneurysm. Common sites for aneurysms include the bifurcation of the middle cerebral artery, the junction of the anterior communicating cerebral artery, and the junction of the posterior communicating artery with the internal carotid artery. If there is complete or partial palsy of the oculomotor nerve, it suggests the rupture of a posterior communicating artery aneurysm.

While hypertension is a risk factor for SAH, a significant increase in blood pressure may occur as a reflex response following the haemorrhage.

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 scan increases to nearly 100% if done within 6 hours of symptom onset. If the CT head scan is negative and there are no contraindications, a lumbar puncture (LP) should be performed to diagnose SAH. It is recommended to perform the LP at least 12 hours after the onset of headache. It is important to note that approximately 3% of patients with a negative CT scan will be confirmed to have had an SAH after undergoing an LP.

The ulnar nerve provides innervation to several muscles in the hand. These include the palmar interossei, dorsal interossei, medial two lumbricals, and the abductor digiti minimi. It is important to note that the lateral two lumbricals are not affected by an ulnar nerve lesion as they are innervated by the median nerve.

Status epilepticus is a condition characterized by continuous seizure activity lasting for 5 minutes or more without the return of consciousness, or recurrent seizures (2 or more) without a period of neurological recovery in between. In such cases, the next step in managing the patient would be to administer a second dose of benzodiazepine. Since the patient already has an intravenous line in place, this would be the most appropriate route to choose.

The management of status epilepticus involves several general measures, which are outlined in the following table:

1st stage (Early status, 0-10 minutes):
– Secure the airway and provide resuscitation
– Administer oxygen
– Assess cardiorespiratory function
– Establish intravenous access

2nd stage (0-30 minutes):
– Institute regular monitoring
– Consider the possibility of non-epileptic status
– Start emergency antiepileptic drug (AED) therapy
– Perform emergency investigations
– Administer glucose (50 ml of 50% solution) and/or intravenous thiamine as Pabrinex if there is any suggestion of alcohol abuse or impaired nutrition
– Treat severe acidosis if present

3rd stage (0-60 minutes):
– Determine the underlying cause of status epilepticus
– Alert the anaesthetist and intensive care unit (ITU)
– Identify and treat any medical complications
– Consider pressor therapy when appropriate

4th stage (30-90 minutes):
– Transfer the patient to the intensive care unit
– Establish intensive care and EEG monitoring
– Initiate intracranial pressure monitoring if necessary
– Start initial long-term, maintenance AED therapy

Emergency investigations for status epilepticus include blood tests for gases, glucose, renal and liver function, calcium and magnesium, full blood count (including platelets), blood clotting, and AED drug levels. Serum and urine samples should be saved for future analysis, including toxicology if the cause of the convulsive status epilepticus is uncertain. A chest radiograph may be performed to evaluate the possibility of aspiration. Additional investigations, such as brain imaging or lumbar puncture, depend on the clinical circumstances.

Monitoring during the management of status epilepticus involves regular neurological observations and measurements of pulse, blood pressure, and temperature. ECG, biochemistry, blood gases, clotting, and blood count should also be monitored.

The most probable diagnosis in this case is a subarachnoid haemorrhage (SAH).

When assessing patients who present with an SAH, they may exhibit focal neurological signs, which can indicate the potential location of the aneurysm. Common areas where aneurysms occur include the bifurcation of the middle cerebral artery, the junction of the anterior communicating cerebral artery, and the junction of the posterior communicating artery with the internal carotid artery. If there is complete or partial paralysis of the oculomotor nerve, it suggests the rupture of a posterior communicating artery aneurysm.

While hypertension is a risk factor for SAH, a significant increase in blood pressure may occur as a reflex response following the haemorrhage.

According to the current guidelines from NICE, alteplase is recommended as a thrombolysis treatment for acute ischaemic stroke. For more information, you can refer to the NICE guidelines on stroke and transient ischaemic attack in individuals over the age of 16.

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 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.

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.

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

The condition is marked by acute capillary haemorrhages, astrocytosis (increase in the number of astrocytes, a type of brain cell), and neuronal death in the upper brainstem and diencephalon. These abnormalities can be visualized using MRI scanning, while CT scanning is not very useful for diagnosis.

If left untreated, most patients with Wernicke’s encephalopathy will go on to develop a 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).

When Wernicke’s encephalopathy is suspected, it is crucial to administer parenteral thiamine (such as Pabrinex) for at least 5 days. Following the parenteral therapy, oral thiamine should be continued.

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.

Cluster headaches are a type of headache that is commonly seen in young men in their 20s. The male to female ratio for this condition is 6:1. Smoking is also known to increase the risk of developing cluster headaches. These headaches occur in clusters, usually lasting for a few weeks every year or two. The pain experienced is severe and typically affects one side of the head, often around or behind the eye. It tends to occur at the same time each day and can cause the patient to become agitated, sometimes resorting to hitting their head against a wall or the floor in an attempt to distract from the pain.

In addition to the intense pain, cluster headaches are also associated with autonomic involvement. This can manifest as various symptoms on the same side as the headache, including conjunctival injection (redness of the eye), rhinorrhea (runny nose), lacrimation (tearing of the eye), miosis (constriction of the pupil), and ptosis (drooping of the eyelid).

On the other hand, migraine with typical aura presents with temporary visual disturbances, such as hemianopia (loss of vision in half of the visual field) or scintillating scotoma (a visual aura that appears as a shimmering or flashing area of distorted vision). Migraine without aura, on the other hand, needs to meet specific criteria set by the International Headache Society. These criteria include having at least five headache attacks lasting between 4 to 72 hours, with the headache having at least two of the following characteristics: unilateral location, pulsating quality, moderate to severe pain intensity, and aggravation by routine physical activity.

During a migraine headache, the patient may also experience symptoms such as nausea and/or vomiting, as well as sensitivity to light (photophobia) and sound (phonophobia). It is important to note that these symptoms should not be attributed to another underlying disorder.

If a patient over the age of 50 presents with a new-onset headache, it raises the possibility of giant cell arteritis (temporal arteritis). Other symptoms and signs that may be associated with this condition include jaw claudication (pain in the jaw when chewing), systemic upset, scalp tenderness, and an elevated erythrocyte sedimentation rate (ESR).

Medication overuse headache is a condition that is suspected when a patient is using multiple medications, often at low doses, without experiencing any relief from their headaches.

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 linked to alcohol abuse and other causes of thiamine deficiency. It is commonly identified by the presence of three main symptoms: acute confusion, ophthalmoplegia (paralysis or weakness of the eye muscles), and ataxia (loss of coordination). Additional signs may include papilloedema (swelling of the optic disc), hearing loss, apathy, dysphagia (difficulty swallowing), memory impairment, and hypothermia. Most cases also involve peripheral neuropathy, primarily affecting the legs.

This condition is characterized by the occurrence of acute capillary hemorrhages, astrocytosis (abnormal increase in astrocytes, a type of brain cell), and neuronal death in the upper brainstem and diencephalon. These abnormalities can be detected through MRI scanning, while CT scanning is not very useful for diagnosis.

If left untreated, most patients with Wernicke’s encephalopathy will develop a condition known as 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 perception of time, and confabulation (fabrication of false memories).

When Wernicke’s encephalopathy is suspected, it is crucial to administer parenteral thiamine (such as Pabrinex) for at least 5 days. Following the parenteral therapy, oral thiamine should be continued.

The current algorithm for treating 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, they should be given an initial dose of benzodiazepine. This can be administered intravenously (IV) or intraosseously (IO) if vascular access is available. Alternatively, buccal midazolam or rectal diazepam can be given if vascular access is not available.

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

Step 3 (10 minutes after the start of step 2):
At this stage, it is necessary to involve senior medical personnel to reassess the child and provide guidance on further management. The recommended approach is as follows:
– If the child is not already receiving 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 instead. The recommended dosage 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.

In the case of this specific child who weighs 25 kg and has already received a dose of lorazepam, they should receive a second dose of 0.1 mg/kg, which amounts to 2.5 mg.

Occlusion of the branches of the basilar artery that supply the midbrain leads to the development of Weber’s syndrome. This condition is characterized by contralateral hemiplegia, which affects the limbs, face, and tongue due to damage to the descending motor tracts within the crus cerebri. Additionally, there are ipsilateral deficits in eye motor activity caused by damage to cranial nerve III.

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.