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.

This patient has developed Wernicke’s encephalopathy, a condition that is associated with alcohol abuse and other causes of thiamine deficiency. It is important to note that the infusion of glucose-containing intravenous fluids without thiamine in a patient with chronic thiamine deficiency can trigger Wernicke’s encephalopathy. In this particular case, it seems that this is what has occurred.

Wernicke’s encephalopathy is typically characterized by a triad of symptoms, which include acute confusion, ophthalmoplegia, and ataxia. Additionally, other possible features of this condition may include papilloedema, hearing loss, apathy, dysphagia, memory impairment, and hypothermia. It is also common for peripheral neuropathy, primarily affecting the legs, to occur in the majority of cases.

This condition is characterized by the presence of acute capillary haemorrhages, astrocytosis, and neuronal death in the upper brainstem and diencephalon. These abnormalities can be visualized through MRI scanning, although 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, an inability to form new memories, disordered time perception, and confabulation.

Patients who are suspected to have Wernicke’s encephalopathy should be promptly treated with parenteral thiamine (such as Pabrinex) for a minimum of 5 days. Following the parenteral therapy, oral thiamine should be administered.

This patient presents with a classic case of temporal arteritis, also known as giant cell arteritis (GCA). Temporal arteritis is a chronic condition characterized by inflammation in the walls of medium and large arteries, specifically granulomatous inflammation. It typically affects individuals who are over 50 years old.

The clinical features of temporal arteritis include headache, tenderness in the scalp, jaw claudication, and episodes of sudden blindness or amaurosis fugax (usually occurring in one eye). Some patients may also experience systemic symptoms such as fever, fatigue, loss of appetite, weight loss, and depression.

Temporal arteritis is often associated with polymyalgia rheumatica (PMR) in about 50% of cases. PMR is characterized by stiffness, aching, and tenderness in the upper arms (bilateral) and pain in the pelvic girdle.

Visual loss is an early and significant complication of temporal arteritis, and once it occurs, it rarely improves. Therefore, early treatment with high-dose corticosteroids is crucial to prevent further visual loss and other ischemic complications. If temporal arteritis is suspected, immediate initiation of high-dose glucocorticosteroid treatment (40 – 60 mg prednisolone daily) is necessary. It is also important to arrange an urgent referral for specialist evaluation, including a same-day ophthalmology assessment for those with visual symptoms, and a temporal artery biopsy.

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

When the paramedian branches of the basilar artery are blocked, it leads to a condition known as medial pontine syndrome. This syndrome is characterized by several symptoms. Firstly, there is contralateral hemiplegia, which refers to paralysis on the opposite side of the body due to damage to the pyramidal tracts. Additionally, there is contralateral loss of joint position sense, vibratory sense, and discriminatory touch, which occurs as a result of damage to the medial lemniscus. Lastly, individuals with medial pontine syndrome may experience double vision caused by paralysis of the lateral rectus muscle, which is due to damage to the sixth cranial nerve.

Dementia with Lewy bodies (DLB) is characterized by several key features, including spontaneous fluctuations in cognitive abilities, visual hallucinations, and Parkinsonism. Visual hallucinations are particularly prevalent in DLB and Parkinson’s disease dementia, which are considered to be part of the same spectrum. While visual hallucinations can occur in other forms of dementia, they are less frequently observed.

Further Reading:

Dementia is a progressive and irreversible clinical syndrome characterized by cognitive and behavioral symptoms. These symptoms include memory loss, impaired reasoning and communication, personality changes, and reduced ability to carry out daily activities. The decline in cognition affects multiple domains of intellectual functioning and is not solely due to normal aging.

To diagnose dementia, a person must have impairment in at least two cognitive domains that significantly impact their daily activities. This impairment cannot be explained by delirium or other major psychiatric disorders. Early-onset dementia refers to dementia that develops before the age of 65.

The most common cause of dementia is Alzheimer’s disease, accounting for 50-75% of cases. Other causes include vascular dementia, dementia with Lewy bodies, and frontotemporal dementia. Less common causes include Parkinson’s disease dementia, Huntington’s disease, prion disease, and metabolic and endocrine disorders.

There are several risk factors for dementia, including age, mild cognitive impairment, genetic predisposition, excess alcohol intake, head injury, depression, learning difficulties, diabetes, obesity, hypertension, smoking, Parkinson’s disease, low social engagement, low physical activity, low educational attainment, hearing impairment, and air pollution.

Assessment of dementia involves taking a history from the patient and ideally a family member or close friend. The person’s current level of cognition and functional capabilities should be compared to their baseline level. Physical examination, blood tests, and cognitive assessment tools can also aid in the diagnosis.

Differential diagnosis for dementia includes normal age-related memory changes, mild cognitive impairment, depression, delirium, vitamin deficiencies, hypothyroidism, adverse drug effects, normal pressure hydrocephalus, and sensory deficits.

Management of dementia involves a multi-disciplinary approach that includes non-pharmacological and pharmacological measures. Non-pharmacological interventions may include driving assessment, modifiable risk factor management, and non-pharmacological therapies to promote cognition and independence. Drug treatments for dementia should be initiated by specialists and may include acetylcholinesterase inhibitors, memantine, and antipsychotics in certain cases.

In summary, dementia is a progressive and irreversible syndrome characterized by cognitive and behavioral symptoms. It has various causes and risk factors, and its management involves a multi-disciplinary approach.

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.

Abducens nerve palsy is often linked to extradural hematoma. When there is a mass effect, downward brain herniation can occur, leading to the involvement of the 6th cranial nerve (abducens nerve, CN VI). This nerve controls the lateral rectus muscle, which is responsible for eye abduction. When the abducens nerve is affected, the lateral rectus muscle is unable to function properly, resulting in an inward turning of the affected eye towards the nose (esotropia).

Further Reading:

Extradural haematoma (EDH) is a collection of blood that forms between the inner surface of the skull and the outer layer of the dura, the dura mater. It is typically caused by head trauma and is often associated with a skull fracture, with the pterion being the most common site of injury. The middle meningeal artery is the most common source of bleeding in EDH.

Clinical features of EDH include a history of head injury with transient loss of consciousness, followed by a lucid interval and gradual loss of consciousness. Other symptoms may include severe headache, sixth cranial nerve palsies, nausea and vomiting, seizures, signs of raised intracranial pressure, and focal neurological deficits.

Imaging of EDH typically shows a biconvex shape and may cause mass effect with brain herniation. It can be differentiated from subdural haematoma by its appearance on imaging.

Management of EDH involves prompt referral to neurosurgery for evacuation of the haematoma. In some cases with a small EDH, conservative management may be considered. With prompt evacuation, the prognosis for EDH is generally good.

Subfalcine herniation occurs when a mass in one side of the brain causes the cingulate gyrus to be pushed under the falx cerebri. This condition often leads to specific neurological symptoms. These symptoms include a motor deficit in the lower limb on the opposite side of the body, bladder incontinence, motor and sensory deficits on the same side of the body as the herniation, and difficulty with speech (dysarthria).

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.

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.