The common peroneal nerve is a branch of the sciatic nerve that provides motor and sensory innervation to the lateral and anterior compartments of the leg, as well as the dorsum of the foot. Damage to this nerve, often caused by fibular neck fracture, results in footdrop and sensory loss in the affected areas.

The sciatic nerve, which originates from the lumbosacral plexus, innervates the posterior compartment of the thigh and indirectly innervates the posterior leg/calf muscles and some intrinsic muscles of the feet. It also provides sensory innervation to the posterolateral leg, lateral foot, and sole of the foot. Sciatica, a common condition that causes pain radiating down the leg, is often caused by irritation of the sciatic nerve root.

The posterior tibial nerve, another branch of the sciatic nerve, supplies motor innervation to the posterior compartment of the leg and sensory innervation to the posterolateral leg, lateral foot, and sole of the foot. Damage to this nerve, often caused by compression or trauma, results in ankle and sole of foot paraesthesiae.

The L5 root innervates muscles responsible for ankle and great toe dorsiflexion, hip abduction, and sensory innervation to the buttocks, posterolateral thigh, and lateral calf. L5 radiculopathy, which causes pain radiating from the lower back to the foot, is a common condition associated with damage to this root.

The deep peroneal nerve, a branch of the common peroneal nerve, innervates the muscles responsible for foot dorsiflexion and provides sensory innervation to the area between the first and second toes. Damage to this nerve, often caused by conditions such as LMD or diabetes, results in footdrop with minimal sensory loss and preserved eversion.

Guillain-Barré syndrome (GBS) can be treated with either plasma exchange or intravenous immunoglobulin (IVIG), both of which are equally effective. The decision on which treatment to use depends on the institution. Plasma exchange is recommended for ambulatory patients within two weeks of symptom onset and for non-ambulatory patients within four weeks. It is most effective when started within seven days of symptom onset, but improvement can still be seen up to 30 days after onset. Patients receiving plasma exchange should be closely monitored for electrolyte abnormalities and coagulopathies, as well as complications such as infection, blood pressure instability, cardiac arrhythmias, and pulmonary embolus. Compared to IVIG, plasma exchange has a higher risk of pneumonia, atelectasis, thrombosis, and hemodynamic difficulties. Urgent referral to oncology is appropriate if the patient has signs of metastatic spinal cord compression. High-dose dexamethasone is not indicated in this case as there is no history of cancer. Intravenous ceftriaxone is used to treat meningitis, which was ruled out by the LP findings. Intravenous itraconazole would be appropriate if fungal meningitis were suspected based on the patient’s history and LP results.

The GCS score for this patient is 654, which can be remembered as MoVE. This scoring system assesses the patient’s level of consciousness by evaluating their eye opening, verbal response, and motor function. In this case, the patient’s eyes are closed but will open in response to pain, earning a score of 2 out of 4. The patient is unable to speak but makes a groaning sound, earning a score of 2 out of 5. The patient also flexes in response to pain, earning a score of 4 out of 6. GCS scores are regularly monitored in patients with head injuries to detect any changes in their neurological status, which could indicate swelling or bleeding.

Understanding the Glasgow Coma Scale for Adults

The Glasgow Coma Scale (GCS) is a tool used to assess the level of consciousness in adults who have suffered a brain injury or other neurological condition. It is based on three components: motor response, verbal response, and eye opening. Each component is scored on a scale from 1 to 6, with a higher score indicating a better level of consciousness.

The motor response component assesses the patient’s ability to move in response to stimuli. A score of 6 indicates that the patient is able to obey commands, while a score of 1 indicates no movement at all.

The verbal response component assesses the patient’s ability to communicate. A score of 5 indicates that the patient is fully oriented, while a score of 1 indicates no verbal response at all.

The eye opening component assesses the patient’s ability to open their eyes. A score of 4 indicates that the patient is able to open their eyes spontaneously, while a score of 1 indicates no eye opening at all.

The GCS score is expressed as a combination of the scores from each component, with the motor response score listed first, followed by the verbal response score, and then the eye opening score. For example, a GCS score of 13, M5 V4 E4 at 21:30 would indicate that the patient had a motor response score of 5, a verbal response score of 4, and an eye opening score of 4 at 9:30 PM.

Overall, the Glasgow Coma Scale is a useful tool for healthcare professionals to assess the level of consciousness in adults with neurological conditions.

The bleeding of damaged bridging veins between the cortex and venous sinuses is the cause of subdural haemorrhage. This condition is the most probable reason for the reduced consciousness in this case. A crescent-shaped lesion is typically seen on CT scans, and it occurs in the subdural space, crossing sutures. Unlike subdural haemorrhage, epidural haemorrhage is linked to the middle meningeal artery, while subarachnoid haemorrhages are associated with vessels of the circle of Willis, such as basilar and anterior circulating arteries.

Understanding Subdural Haemorrhage

A subdural haemorrhage is a condition where blood collects deep to the dural layer of the meninges. This collection of blood is not within the brain substance and is referred to as an ‘extra-axial’ or ‘extrinsic’ lesion. Subdural haematomas can be classified based on their age, which includes acute, subacute, and chronic. Although they occur within the same anatomical compartment, acute and chronic subdurals have significant differences in terms of their mechanisms, associated clinical features, and management.

An acute subdural haematoma is a collection of fresh blood within the subdural space and is commonly caused by high-impact trauma. This type of haematoma is associated with high-impact injuries, and there is often other underlying brain injuries. Symptoms and presentation vary depending on the size of the compressive acute subdural haematoma and the associated injuries. CT imaging is the first-line investigation, and surgical options include monitoring of intracranial pressure and decompressive craniectomy.

On the other hand, a chronic subdural haematoma is a collection of blood within the subdural space that has been present for weeks to months. Elderly and alcoholic patients are particularly at risk of subdural haematomas since they have brain atrophy and therefore fragile or taut bridging veins. Infants also have fragile bridging veins and can rupture in shaken baby syndrome. If the chronic subdural is an incidental finding or if it is small in size with no associated neurological deficit, it can be managed conservatively. However, if the patient is confused, has an associated neurological deficit, or has severe imaging findings, surgical decompression with burr holes is required.

After a subarachnoid haemorrhage, the preferred treatment for most intracranial aneurysms is coiling by an interventional neuroradiologist. This is the most probable course of action given the patient’s stable condition. If the patient showed signs of raised intracranial pressure, such as haemodynamic instability or a change in GCS, craniotomy and clipping of the aneurysm might be considered. However, regardless of whether the aneurysm is coiled or clipped, the primary objective is to prevent further bleeding by mechanically occluding the aneurysm, preferably within the first 24 hours. Therefore, the other options are unlikely to be the correct and definitive management for the patient’s condition.

A subarachnoid haemorrhage (SAH) is a type of bleeding that occurs within the subarachnoid space of the meninges in the brain. It can be caused by head injury or occur spontaneously. Spontaneous SAH is often caused by an intracranial aneurysm, which accounts for around 85% of cases. Other causes include arteriovenous malformation, pituitary apoplexy, and mycotic aneurysms. The classic symptoms of SAH include a sudden and severe headache, nausea and vomiting, meningism, coma, seizures, and ECG changes.

The first-line investigation for SAH is a non-contrast CT head, which can detect acute blood in the basal cisterns, sulci, and ventricular system. If the CT is normal within 6 hours of symptom onset, a lumbar puncture is not recommended. However, if the CT is normal after 6 hours, a lumbar puncture should be performed at least 12 hours after symptom onset to check for xanthochromia and other CSF findings consistent with SAH. If SAH is confirmed, referral to neurosurgery is necessary to identify the underlying cause and provide urgent treatment.

Management of aneurysmal SAH involves supportive care, such as bed rest, analgesia, and venous thromboembolism prophylaxis. Vasospasm is prevented with oral nimodipine, and intracranial aneurysms require prompt intervention to prevent rebleeding. Most aneurysms are treated with a coil by interventional neuroradiologists, but some require a craniotomy and clipping by a neurosurgeon. Complications of aneurysmal SAH include re-bleeding, hydrocephalus, vasospasm, and hyponatraemia. Predictive factors for SAH include conscious level on admission, age, and amount of blood visible on CT head.

Lifelong use of aspirin and dipyridamole. Age: 55.

The Royal College of Physicians (RCP) and NICE have published guidelines on the diagnosis and management of patients following a stroke. The management of acute stroke includes maintaining normal levels of blood glucose, hydration, oxygen saturation, and temperature. Blood pressure should not be lowered in the acute phase unless there are complications. Aspirin should be given as soon as possible if a haemorrhagic stroke has been excluded. Anticoagulants should not be started until brain imaging has excluded haemorrhage. Thrombolysis with alteplase should only be given if administered within 4.5 hours of onset of stroke symptoms and haemorrhage has been definitively excluded. Mechanical thrombectomy is a new treatment option for patients with an acute ischaemic stroke. NICE recommends thrombectomy for people who have acute ischaemic stroke and confirmed occlusion of the proximal anterior circulation demonstrated by computed tomographic angiography or magnetic resonance angiography. Secondary prevention includes the use of clopidogrel and dipyridamole. Carotid artery endarterectomy should only be considered if carotid stenosis is greater than 70% according to ECST criteria or greater than 50% according to NASCET criteria.

NICE Guidelines for Investigating Head Injuries in Adults

Head injuries can be serious and require prompt medical attention. The National Institute for Health and Care Excellence (NICE) has provided clear guidelines for healthcare professionals to determine which adult patients need further investigation with a CT head scan. Patients who require immediate CT head scans include those with a Glasgow Coma Scale (GCS) score of less than 13 on initial assessment, suspected open or depressed skull fractures, signs of basal skull fractures, post-traumatic seizures, focal neurological deficits, and more than one episode of vomiting.

For patients with any loss of consciousness or amnesia since the injury, a CT head scan within 8 hours is recommended for those who are 65 years or older, have a history of bleeding or clotting disorders, experienced a dangerous mechanism of injury, or have more than 30 minutes of retrograde amnesia of events immediately before the head injury. Additionally, patients on warfarin who have sustained a head injury with no other indications for a CT head scan should also receive a scan within 8 hours of the injury.

It is important for healthcare professionals to follow these guidelines to ensure that patients receive appropriate and timely care for their head injuries. By identifying those who require further investigation, healthcare professionals can provide the necessary treatment and support to prevent further complications and improve patient outcomes.

Consider herpes simplex encephalitis as the possible cause for the observed temporal lobe changes on the CT head.

Understanding Herpes Simplex Encephalitis

Herpes simplex encephalitis is a common topic in medical exams. This viral infection affects the temporal lobes of the brain, causing symptoms such as fever, headache, seizures, and vomiting. Focal features like aphasia may also be present. It is important to note that peripheral lesions, such as cold sores, are not related to the presence of HSV encephalitis.

HSV-1 is responsible for 95% of cases in adults and typically affects the temporal and inferior frontal lobes. Diagnosis is made through CSF analysis, PCR for HSV, and imaging studies like CT or MRI. EEG patterns may also show lateralized periodic discharges at 2 Hz.

Treatment involves intravenous aciclovir, and prompt initiation of treatment is crucial for a good prognosis. If treatment is started early, the mortality rate is around 10-20%. However, if left untreated, the mortality rate can approach 80%.

In summary, understanding the symptoms, pathophysiology, and treatment of herpes simplex encephalitis is important for medical professionals and students alike. Early recognition and treatment can greatly improve outcomes for patients with this condition.

The pain experienced by this patient is indicative of trigeminal neuralgia, displaying typical characteristics.

Understanding Trigeminal Neuralgia

Trigeminal neuralgia is a type of pain syndrome that is characterized by severe pain on one side of the face. While most cases are idiopathic, some may be caused by compression of the trigeminal roots due to tumors or vascular problems. According to the International Headache Society, trigeminal neuralgia is defined as a disorder that causes brief electric shock-like pains that are limited to one or more divisions of the trigeminal nerve. The pain is often triggered by light touch, such as washing, shaving, or brushing teeth, and can occur spontaneously. Certain areas of the face, such as the nasolabial fold or chin, may be more susceptible to pain. The pain may also remit for varying periods.

Red flag symptoms and signs that suggest a serious underlying cause include sensory changes, ear problems, a history of skin or oral lesions that could spread perineurally, pain only in the ophthalmic division of the trigeminal nerve, optic neuritis, a family history of multiple sclerosis, and onset before the age of 40.

The first-line treatment for trigeminal neuralgia is carbamazepine. If there is a failure to respond to treatment or atypical features are present, such as onset before the age of 50, referral to neurology is recommended. Understanding the symptoms and management of trigeminal neuralgia is important for proper diagnosis and treatment.

The patient’s symptoms suggest Guillain-Barré syndrome, an acute inflammatory polyneuropathy that often occurs after a viral or bacterial infection. This condition is characterized by progressive, bilateral, ascending weakness that typically starts in the legs and spreads to the arms, respiratory muscles, and bulbar muscles. Areflexia is also present. Treatment may involve respiratory support, intravenous immunoglobulins, and plasma exchange. Most patients recover completely or almost completely, but the mortality rate is around 10%.

Mononeuritis multiplex is a rare condition that affects multiple peripheral and/or cranial nerves. Symptoms are usually asymmetrical and evolve at different times and with different degrees of severity. Diabetes is a common cause, but other systemic disorders can also be implicated. The patient’s symmetrical weakness affecting both legs at the same time is more consistent with a polyneuropathy than mononeuritis multiplex.

The patient’s symptoms do not fit with a diagnosis of multiple sclerosis, which typically presents with relapsing-remitting disease characterized by acute flairs and some improvement between flairs. MS is more common in females and onset peaks between 20 and 40 years. The patient’s symmetrical distribution of symptoms and rapid progression to affect knees and hips make MS unlikely.

Myasthenia gravis is an autoimmune disorder associated with antibodies to acetylcholine receptors at the neuromuscular junction. Patients typically display weakness of the periocular, facial, bulbar, and girdle muscles, with symptoms worsening with prolonged use. The patient’s symmetrical distal weakness is atypical for myasthenia gravis, which tends to affect proximal muscles first.

Polymyositis is a connective tissue disease that affects striated muscle, with symmetrical proximal muscle/limb girdle weakness being a prominent feature. Muscle tenderness and atrophy may also be present. The patient’s distal muscle weakness is not consistent with polymyositis.

Compared to other classes of medications, dopamine agonists such as ropinirole pose a higher risk of causing hallucinations in individuals with Parkinson’s disease. On the other hand, MAO-B inhibitors like selegiline and COMPT inhibitors like entacapone have little to no reported risk of causing hallucinations. Tiotropium is commonly prescribed for the treatment of COPD, while oxybutynin is used to manage bladder overactivity.

Management of Parkinson’s Disease: Medications and Considerations

Parkinson’s disease is a complex condition that requires specialized expertise in movement disorders for diagnosis and management. However, all healthcare professionals should be familiar with the medications used to treat Parkinson’s disease due to its prevalence. The National Institute for Health and Care Excellence (NICE) published guidelines in 2017 to aid in the management of Parkinson’s disease.

For first-line treatment, levodopa is recommended if motor symptoms are affecting the patient’s quality of life. If motor symptoms are not affecting the patient’s quality of life, dopamine agonists (non-ergot derived), levodopa, or monoamine oxidase B (MAO-B) inhibitors may be used. NICE provides tables to aid in decision-making regarding the use of these medications, taking into account their effects on motor symptoms, activities of daily living, motor complications, and adverse events.

If a patient continues to have symptoms despite optimal levodopa treatment or has developed dyskinesia, NICE recommends the addition of a dopamine agonist, MAO-B inhibitor, or catechol-O-methyl transferase (COMT) inhibitor as an adjunct. Other considerations in Parkinson’s disease management include the risk of acute akinesia or neuroleptic malignant syndrome if medication is not taken or absorbed, the potential for impulse control disorders with dopaminergic therapy, and the need to adjust medication if excessive daytime sleepiness or orthostatic hypotension develops.

Specific medications used in Parkinson’s disease management include levodopa, dopamine receptor agonists, MAO-B inhibitors, amantadine, COMT inhibitors, and antimuscarinics. Each medication has its own set of benefits and potential adverse effects, which should be carefully considered when selecting a treatment plan. Overall, the management of Parkinson’s disease requires a comprehensive approach that takes into account the individual needs and circumstances of each patient.

Trigeminal Neuralgia: Diagnosis and Treatment

Trigeminal neuralgia is a condition characterized by sharp, shooting pain in the distribution of one or more branches of the trigeminal nerve. While the cause is unknown, it can be due to compression of the nerve as it exits the foramen. The pain is intermittent and often exacerbated by light touch, eating, talking, or exposure to the cold.

Carbamazepine is the first-line treatment for trigeminal neuralgia, with an initial dose of 100 mg up to twice daily. The dosage can be increased in increments of 100-200 mg every 2 weeks until the pain is under control.

Contrary to popular belief, trigeminal neuralgia usually affects the face unilaterally, with only 3% of cases being bilateral. A CT scan of the head is not recommended for all patients with the diagnosis of trigeminal neuralgia, but may be necessary if red flag symptoms are present.

It is important to note that patients with trigeminal neuralgia do not typically experience constant pain, as the pain is episodic in frequency. Tramadol is not the first-line treatment for trigeminal pain, carbamazepine is.

Pre-menopausal women with oestrogen receptor-positive breast cancer are managed using Tamoxifen.
Tamoxifen is ineffective in treating oestrogen receptor-negative breast cancer or ovarian cancer.
However, Tamoxifen may increase the risk of endometrial cancer.
Colorectal cancer is not treated with Tamoxifen.

Anti-oestrogen drugs are used in the management of oestrogen receptor-positive breast cancer. Selective oEstrogen Receptor Modulators (SERM) such as Tamoxifen act as an oestrogen receptor antagonist and partial agonist. However, Tamoxifen can cause adverse effects such as menstrual disturbance, hot flushes, venous thromboembolism, and endometrial cancer. On the other hand, aromatase inhibitors like Anastrozole and Letrozole reduce peripheral oestrogen synthesis, which is important in postmenopausal women. Anastrozole is used for ER +ve breast cancer in this group. However, aromatase inhibitors can cause adverse effects such as osteoporosis, hot flushes, arthralgia, myalgia, and insomnia. NICE recommends a DEXA scan when initiating a patient on aromatase inhibitors for breast cancer.

For the prophylactic management of migraines in a patient with a history of asthma, the recommended medication is topiramate. Propranolol is an alternative first-line option, but should be avoided in patients with asthma. Amitriptyline is a second-line drug for those who are not responsive to initial prophylactic treatment. Diclofenac is an NSAID used for acute management of migraines, while triptans like sumatriptan are used for acute treatment but not prophylaxis. It should be noted that topiramate is teratogenic and should be avoided in women of childbearing age.

Managing Migraines: Guidelines and Treatment Options

Migraines can be debilitating and affect a significant portion of the population. To manage migraines, it is important to understand the different treatment options available. According to the National Institute for Health and Care Excellence (NICE) guidelines, acute treatment for migraines involves a combination of an oral triptan and an NSAID or paracetamol. For young people aged 12-17 years, a nasal triptan may be preferred. If these measures are not effective, non-oral preparations of metoclopramide or prochlorperazine may be considered, along with a non-oral NSAID or triptan.

Prophylaxis should be given if patients are experiencing two or more attacks per month. NICE recommends topiramate or propranolol, depending on the patient’s preference, comorbidities, and risk of adverse events. Propranolol is preferred in women of childbearing age as topiramate may be teratogenic and reduce the effectiveness of hormonal contraceptives. Acupuncture and riboflavin may also be effective in reducing migraine frequency and intensity for some people. For women with predictable menstrual migraines, frovatriptan or zolmitriptan may be recommended as a type of mini-prophylaxis.

Specialists may consider other treatment options, such as candesartan or monoclonal antibodies directed against the calcitonin gene-related peptide (CGRP) receptor, like erenumab. However, pizotifen is no longer recommended due to common adverse effects like weight gain and drowsiness. It is important to exercise caution with young patients as acute dystonic reactions may develop. By following these guidelines and considering various treatment options, migraines can be effectively managed.

Weight gain can be a side effect of taking sodium valproate.

Sodium Valproate: Uses and Adverse Effects

Sodium valproate is a medication commonly used to manage epilepsy, particularly for generalised seizures. Its mechanism of action involves increasing the activity of GABA in the brain. However, the use of sodium valproate during pregnancy is strongly discouraged due to its teratogenic effects, which can lead to neural tube defects and neurodevelopmental delays in children. Women of childbearing age should only use this medication if it is absolutely necessary and under the guidance of a specialist neurological or psychiatric advisor.

Aside from its teratogenic effects, sodium valproate can also inhibit P450 enzymes, leading to gastrointestinal issues such as nausea, increased appetite, and weight gain. Other adverse effects include alopecia, ataxia, tremors, hepatotoxicity, pancreatitis, thrombocytopenia, hyponatremia, and hyperammonemic encephalopathy. In cases where hyperammonemic encephalopathy develops, L-carnitine may be used as a treatment option.

Overall, while sodium valproate can be an effective medication for managing epilepsy, its use should be carefully considered and monitored due to its potential adverse effects, particularly during pregnancy.

Immediate CT scan is necessary to evaluate for raised intracranial pressure and tentorial herniation in a patient with a sluggishly responsive unilaterally dilated pupil. This is the most pressing concern, given the patient’s reduced GCS. Although other investigations will be necessary, the CT brain is the most critical test, as the patient may require urgent neurosurgical intervention to save their life.

Patients with head injuries should be managed according to ATLS principles and extracranial injuries should be managed alongside cranial trauma. There are different types of traumatic brain injuries, including extradural hematoma, subdural hematoma, and subarachnoid hemorrhage. Primary brain injury may be focal or diffuse, and secondary brain injury can occur due to cerebral edema, ischemia, infection, or herniation. Management may include IV mannitol/frusemide, decompressive craniotomy, and ICP monitoring. Pupillary findings can provide information on the location and severity of the injury.

Understanding the Glasgow Coma Scale for Adults

The Glasgow Coma Scale (GCS) is a tool used to assess the level of consciousness in adults who have suffered a brain injury or other neurological condition. It is based on three components: motor response, verbal response, and eye opening. Each component is scored on a scale from 1 to 6, with a higher score indicating a better level of consciousness.

The motor response component assesses the patient’s ability to move in response to stimuli. A score of 6 indicates that the patient is able to obey commands, while a score of 1 indicates no movement at all.

The verbal response component assesses the patient’s ability to communicate. A score of 5 indicates that the patient is fully oriented, while a score of 1 indicates no verbal response at all.

The eye opening component assesses the patient’s ability to open their eyes. A score of 4 indicates that the patient is able to open their eyes spontaneously, while a score of 1 indicates no eye opening at all.

The GCS score is expressed as a combination of the scores from each component, with the motor response score listed first, followed by the verbal response score, and then the eye opening score. For example, a GCS score of 13, M5 V4 E4 at 21:30 would indicate that the patient had a motor response score of 5, a verbal response score of 4, and an eye opening score of 4 at 9:30 PM.

Overall, the Glasgow Coma Scale is a useful tool for healthcare professionals to assess the level of consciousness in adults with neurological conditions.

For patients with an acute ischaemic stroke who present within 4.5 hours, the recommended treatment is a combination of thrombolysis and thrombectomy. Thrombolysis involves the use of alteplase, a tissue plasminogen activator that breaks down the clot, while thrombectomy physically removes the clot using a specialized device inserted through the femoral artery. In this case, as the patient has confirmed occlusion of the proximal anterior circulation, both thrombolysis and thrombectomy should be performed together for the best possible outcome. While alteplase alone can be considered if thrombectomy is not available, a better prognosis is more likely with the combination treatment. It would not be appropriate to perform thrombectomy alone without considering thrombolysis, as the patient is presenting within the window for thrombolysis and should be considered for both in combination according to the guidelines.

The Royal College of Physicians (RCP) and NICE have published guidelines on the diagnosis and management of patients following a stroke. The management of acute stroke includes maintaining normal levels of blood glucose, hydration, oxygen saturation, and temperature. Blood pressure should not be lowered in the acute phase unless there are complications. Aspirin should be given as soon as possible if a haemorrhagic stroke has been excluded. Anticoagulants should not be started until brain imaging has excluded haemorrhage. Thrombolysis with alteplase should only be given if administered within 4.5 hours of onset of stroke symptoms and haemorrhage has been definitively excluded. Mechanical thrombectomy is a new treatment option for patients with an acute ischaemic stroke. NICE recommends thrombectomy for people who have acute ischaemic stroke and confirmed occlusion of the proximal anterior circulation demonstrated by computed tomographic angiography or magnetic resonance angiography. Secondary prevention includes the use of clopidogrel and dipyridamole. Carotid artery endarterectomy should only be considered if carotid stenosis is greater than 70% according to ECST criteria or greater than 50% according to NASCET criteria.

Differential diagnosis for a patient with subacute cerebellar dysfunction and normal imaging

Paraneoplastic cerebellum syndrome, multiple sclerosis, cerebellar metastasis, malignant meningitis, and Wernicke’s encephalopathy are among the possible diagnoses for a patient presenting with subacute onset of cerebellar signs and normal imaging.

Paraneoplastic cerebellum syndrome is a rare immune-mediated complication of many cancers, which may be diagnosed before the underlying tumour. Symptoms develop rapidly and include dizziness, nausea, vertigo, nystagmus, ataxia, oscillopsia, dysarthria, tremor, dysphagia, and blurry vision. MRI may be normal, but CSF may show raised protein and anti-neuronal antibodies.

Multiple sclerosis is more common in women and usually presents with transient episodes of visual change or limb weakness/paraesthesiae, as well as bladder and cerebellar dysfunction. MRI may visualise plaques of demyelination, and CSF shows oligoclonal bands.

Cerebellar metastasis could occur in breast cancer, but it would be visualised on MRI.

Malignant meningitis occurs when cancer spreads to the meninges and presents with confusion, headaches, and weakness. Imaging and CSF would be abnormal.

Wernicke’s encephalopathy is due to thiamine deficiency, typically seen in alcoholics, and presents with acute confusional state, ophthalmoplegia, and gait ataxia. Dysarthria is not usually a feature. Thiamine deficiency is not suggested by this patient’s history.

The correct answer is cubital tunnel syndrome. This condition is characterized by ulnar nerve neuropathy, which affects the sensory innervation of the palmar and dorsal aspects of 1.5 fingers medially. It can also cause wasting and paralysis of intrinsic hand muscles (except lateral two lumbricals) and the hypothenar muscles. To test for ulnar neuropathy, Froment’s test can be used to assess the function of the adductor pollicis muscle.

Axillary nerve neuropathy is not the correct answer. The axillary nerve has both motor and sensory functions, innervating the deltoid and teres minor muscles, as well as providing sensory innervation to the skin over the lower two-thirds of the posterior part of the deltoid and the long head of the triceps brachii.

C8/T1 radiculopathy is also not the correct answer. While it can mimic ulnar nerve neuropathy, the preserved sensation of the forearm would suggest cubital tunnel syndrome instead. The medial antebrachial cutaneous nerve (C8 and T1) provides sensation to the medial forearm, not the ulnar nerve.

Carpal tunnel syndrome is also not the correct answer. This condition is caused by median nerve dysfunction, resulting in sensory loss over the lateral 3.5 digits and loss of motor function to the flexor muscles of the forearm and hand, as well as those responsible for thumb movement.

The Ulnar Nerve: Overview, Branches, and Patterns of Damage

The ulnar nerve is a nerve that arises from the medial cord of the brachial plexus, specifically from the C8 and T1 spinal nerves. It provides motor innervation to several muscles in the hand, including the medial two lumbricals, adductor pollicis, interossei, hypothenar muscles (abductor digiti minimi, flexor digiti minimi), and flexor carpi ulnaris. It also provides sensory innervation to the medial 1 1/2 fingers on both the palmar and dorsal aspects.

The ulnar nerve travels through the posteromedial aspect of the upper arm before entering the palm of the hand via the Guyon’s canal, which is located superficial to the flexor retinaculum and lateral to the pisiform bone. The nerve has several branches, including the muscular branch, palmar cutaneous branch, dorsal cutaneous branch, superficial branch, and deep branch. These branches supply various muscles and skin areas in the hand.

Damage to the ulnar nerve can occur at the wrist or elbow. When damaged at the wrist, it can result in a claw hand deformity, which involves hyperextension of the metacarpophalangeal joints and flexion at the distal and proximal interphalangeal joints of the 4th and 5th digits. There may also be wasting and paralysis of intrinsic hand muscles (except lateral two lumbricals) and hypothenar muscles, as well as sensory loss to the medial 1 1/2 fingers. When damaged at the elbow, the same symptoms may occur, but with the addition of radial deviation of the wrist. It is important to note that in distal lesions, the clawing may be more severe, which is known as the ulnar paradox.