Neurology Flashcards

Question

Motor neuron disease

Answer 1

Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs. It rarely presents before 40 years and various patterns of disease are recognised including amyotrophic lateral sclerosis, progressive muscular atrophy and bulbar palsy. There are a number of clues which point towards a diagnosis of motor neuron disease: fasciculations the absence of sensory signs/symptoms\* the mixture of lower motor neuron and upper motor neuron signs wasting of the small hand muscles/tibialis anterior is common Other features doesn't affect external ocular muscles no cerebellar signs abdominal reflexes are usually preserved and sphincter dysfunction if present is a late feature The diagnosis of motor neuron disease is clinical, but nerve conduction studies will show normal motor conduction and can help exclude a neuropathy. Electromyography shows a reduced number of action potentials with increased amplitude. MRI is usually performed to exclude the differential diagnosis of cervical cord compression and myelopathy \*vague sensory symptoms may occur early in the disease (e.g. limb pain) but 'never' sensory signs

Answer 2

Patient's with multiple sclerosis (MS) may present with non-specific features, for example around 75% of patients have significant lethargy. Diagnosis can be made on the basis of two or more relapses and either objective clinical evidence of two or more lesions or objective clinical evidence of one lesion together with reasonable historical evidence of a previous relapse. Visual optic neuritis: common presenting feature optic atrophy Uhthoff's phenomenon: worsening of vision following rise in body temperature internuclear ophthalmoplegia Sensory pins/needles numbness trigeminal neuralgia Lhermitte's syndrome: paraesthesiae in limbs on neck flexion Motor spastic weakness: most commonly seen in the legs Cerebellar ataxia: more often seen during an acute relapse than as a presenting symptom tremor Others urinary incontinence sexual dysfunction intellectual deterioration Multiple sclerosis: management Treatment in multiple sclerosis is focused at reducing the frequency and duration of relapses. There is no cure. Acute relapse High dose steroids (e.g. oral or IV methylprednisolone) may be given for 5 days to shorten the length of an acute relapse. It should be noted that steroids shorten the duration of a relapse and do not alter the degree of recovery (i.e. whether a patient returns to baseline function) Disease modifying drugs Beta-interferon has been shown to reduce the relapse rate by up to 30%. Certain criteria have to be met before it is used: relapsing-remitting disease + 2 relapses in past 2 years + able to walk 100m unaided secondary progressive disease + 2 relapses in past 2 years + able to walk 10m (aided or unaided) reduces number of relapses and MRI changes, however doesn't reduce overall disability Other drugs used in the management of multiple sclerosis include: glatiramer acetate: immunomodulating drug - acts as an 'immune decoy' natalizumab: a recombinant monoclonal antibody that antagonises Alpha-4 Beta-1-integrin found on the surface of leucocytes, thus inhibiting migration of leucocytes across the endothelium across the blood-brain barrier fingolimod: sphingosine 1-phosphate receptor modulator, prevents lymphocytes from leaving lymph nodes. An oral formulation is available Some specific problems Fatigue once other problems (e.g. anaemia, thyroid or depression) have been excluded NICE recommend a trial of amantadine other options include mindfulness training and CBT Spasticity baclofen and gabapentin are first-line. Other options include diazepam, dantrolene and tizanidine physiotherapy is important cannabis and botox are undergoing evalulation Bladder dysfunction may take the form of urgency, incontinence, overflow etc guidelines stress the importance of getting an ultrasound first to assess bladder emptying - anticholinergics may worsen symptoms in some patients if significant residual volume → intermittent self-catheterisation if no significant residual volume → anticholinergics may improve urinary frequency Oscillopsia (visual fields apper to oscillate) gabapentin is first-line

Answer 3

Neuroleptic malignant syndrome is a rare but dangerous condition seen in patients taking antipsychotic medication. It carries a mortality of up to 10% and can also occur with atypical antipsychotics. It may also occur with dopaminergic drugs (such as levodopa) for Parkinson's disease, usually when the drug is suddenly stopped or the dose reduced. The pathophysiology is unknown but one theory is that the dopamine blockade induced by antipsychotics triggers massive glutamate release and subsequent neurotoxicity and muscle damage. It occurs within hours to days of starting an antipsychotic (antipsychotics are also known as neuroleptics, hence the name) and the typical features are: pyrexia muscle rigidity autonomic lability: typical features include hypertension, tachycardia and tachypnoea agitated delirium with confusion A raised creatine kinase is present in most cases. Acute kidney injury (secondary to rhabdomyolysis) may develop in severe cases. A leukocytosis may also be seen Management stop antipsychotic patients should be transferred to a medical ward if they are on a psychiatric ward and often they are nursed in intensive care units IV fluids to prevent renal failure dantrolene may be useful in selected cases thought to work by decreasing excitation-contraction coupling in skeletal muscle by binding to the ryanodine receptor, and decreasing the release of calcium from the sarcoplasmic reticulum bromocriptine, dopamine agonist, may also be used

Answer 4

Neuropathic pain may be defined as pain which arises following damage or disruption of the nervous system. It is often difficult to treat and responds poorly to standard analgesia. Examples include: diabetic neuropathy post-herpetic neuralgia trigeminal neuralgia prolapsed intervertebral disc NICE updated their guidance on the management of neuropathic pain in 2013: first-line treatment\*: amitriptyline, duloxetine, gabapentin or pregabalin if the first-line drug treatment does not work try one of the other 3 drugs tramadol may be used as 'rescue therapy' for exacerbations of neuropathic pain topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia) pain management clinics may be useful in patients with resistant problems \*please note that for some specific conditions the guidance may vary. For example carbamazepine is used first-line for trigeminal neuralgia Neuropathic pain Neuropathic pain may be defined as pain which arises following damage or disruption of the nervous system. It is often difficult to treat and responds poorly to standard analgesia. Examples include: diabetic neuropathy post-herpetic neuralgia trigeminal neuralgia prolapsed intervertebral disc NICE updated their guidance on the management of neuropathic pain in 2013: first-line treatment\*: amitriptyline, duloxetine, gabapentin or pregabalin if the first-line drug treatment does not work try one of the other 3 drugs tramadol may be used as 'rescue therapy' for exacerbations of neuropathic pain topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia) pain management clinics may be useful in patients with resistant problems \*please note that for some specific conditions the guidance may vary. For example carbamazepine is used first-line for trigeminal neuralgia

Answer 5

Causes of Parkinsonism Parkinson's disease drug-induced e.g. antipsychotics, metoclopramide\* progressive supranuclear palsy multiple system atrophy Wilson's disease post-encephalitis dementia pugilistica (secondary to chronic head trauma e.g. boxing) toxins: carbon monoxide, MPTP \*Domperidone does not cross the blood-brain barrier and therefore does not cause extra-pyramidal side-effects. Levodopa should be offered for patients with newly diagnosed Parkinson's who have motor symptoms affecting their quality of life Essential tremor is an AD condition that is made worse when arms are outstretched, made better by alcohol and propranolol Parkinsons disease should only be diagnosed, and management initiated, by a specialist with expertise in movement disorders. However, it is important for all doctors to be aware of the medications used in Parkinson's given the prevalence of this condition. NICE published guidelines in 2017 regarding the management of Parkinson's disease. For first-line treatment: if the motor symptoms are affecting the patient's quality of life: levodopa if the motor symptoms are not affecting the patient's quality of life: dopamine agonist (non-ergot derived), levodopa or monoamine oxidase B (MAO‑B) inhibitor Specific points regarding Parkinson's medication NICE reminds us of the risk of acute akinesia or neuroleptic malignant syndrome if medication is not taken/absorbed (for example due to gastroenteritis) and advise against giving patients a 'drug holiday' for the same reason. Impulse control disorders have become a significant issue in recent years. These can occur with any dopaminergic therapy but are more common with: dopamine agonist therapy a history of previous impulsive behaviours a history of alcohol consumption and/or smoking If excessive daytime sleepiness develops then patients should not drive. Medication should be adjusted to control symptoms. Modafinil can be considered if alternative strategies fail. If orthostatic hypotension develops then a medication review looking at potential causes should be done. If symptoms persist then midodrine (acts on peripheral alpha-adrenergic receptors to increase arterial resistance) can be considered. Consider glycopyrronium bromide to manage drooling of saliva in people with Parkinson's disease. Further information regarding specific anti-Parkinson's medication Levodopa usually combined with a decarboxylase inhibitor (e.g. carbidopa or benserazide) to prevent peripheral metabolism of levodopa to dopamine reduced effectiveness with time (usually by 2 years) unwanted effects: dyskinesia (involuntary writhing movements), 'on-off' effect, dry mouth, anorexia, palpitations, postural hypotension, psychosis, drowsiness no use in neuroleptic induced parkinsonism it is important not to acutely stop levodopa, for example if a patient is admitted to hospital. If a patient with Parkinson's disease cannot take levodopa orally, they can be given a dopamine agonist patch as rescue medication to prevent acute dystonia Dopamine receptor agonists e.g. bromocriptine, ropinirole, cabergoline, apomorphine ergot-derived dopamine receptor agonists (bromocriptine, cabergoline) have been associated with pulmonary, retroperitoneal and cardiac fibrosis. The Committee on Safety of Medicines advice that an echocardiogram, ESR, creatinine and chest x-ray should be obtained prior to treatment and patients should be closely monitored patients should be warned about the potential for dopamine receptor agonists to cause impulse control disorders and excessive daytime somnolence more likely than levodopa to cause hallucinations in older patients. Nasal congestion and postural hypotension are also seen in some patients MAO-B (Monoamine Oxidase-B) inhibitors e.g. selegiline inhibits the breakdown of dopamine secreted by the dopaminergic neurons Amantadine mechanism is not fully understood, probably increases dopamine release and inhibits its uptake at dopaminergic synapses side-effects include ataxia, slurred speech, confusion, dizziness and livedo reticularis COMT (Catechol-O-Methyl Transferase) inhibitors e.g. entacapone, tolcapone COMT is an enzyme involved in the breakdown of dopamine, and hence may be used as an adjunct to levodopa therapy used in conjunction with levodopa in patients with established PD Antimuscarinics block cholinergic receptors now used more to treat drug-induced parkinsonism rather than idiopathic Parkinson's disease help tremor and rigidity e.g. procyclidine, benzotropine, trihexyphenidyl (benzhexol)

Answer 6

Peripheral neuropathy may be divided into conditions which predominately cause a motor or sensory loss Predominately motor loss Guillain-Barre syndrome porphyria lead poisoning hereditary sensorimotor neuropathies (HSMN) - Charcot-Marie-Tooth chronic inflammatory demyelinating polyneuropathy (CIDP) diphtheria Predominately sensory loss diabetes uraemia leprosy alcoholism vitamin B12 deficiency amyloidosis Alcoholic neuropathy secondary to both direct toxic effects and reduced absorption of B vitamins sensory symptoms typically present prior to motor symptoms Vitamin B12 deficiency subacute combined degeneration of spinal cord dorsal column usually affected first (joint position, vibration) prior to distal paraesthesia

Answer 7

Sodium valproate is used in the management of epilepsy and is first-line therapy for generalised seizures. It works by increasing GABA activity. Adverse effects P450 inhibitor gastrointestinal: nausea increased appetite and weight gain alopecia: regrowth may be curly ataxia tremor hepatotoxicity pancreatitis thrombocytopaenia teratogenic hyponatraemia hyperammonemic encephalopathy: L-carnitine may be used as treatment if this develops Sodium valproate may cause weight gain Phenytoin Phenytoin is used in the management of seizures. Mechanism of action binds to sodium channels increasing their refractory period Adverse effects Phenytoin is associated with a large number of adverse effects. These may be divided into acute, chronic, idiosyncratic and teratogenic. Phenytoin is also an inducer of the P450 system. Acute initially: dizziness, diplopia, nystagmus, slurred speech, ataxia later: confusion, seizures Chronic common: gingival hyperplasia (secondary to increased expression of platelet derived growth factor, PDGF), hirsutism, coarsening of facial features, drowsiness megaloblastic anaemia (secondary to altered folate metabolism) peripheral neuropathy enhanced vitamin D metabolism causing osteomalacia lymphadenopathy dyskinesia Idiosyncratic fever rashes, including severe reactions such as toxic epidermal necrolysis hepatitis Dupuytren's contracture\* aplastic anaemia drug-induced lupus Teratogenic associated with cleft palate and congenital heart disease Monitoring Phenytoin levels do not need to be monitored routinely but trough levels, immediately before dose should be checked if: adjustment of phenytoin dose suspected toxicity detection of non-adherence to the prescribed medication \*although not listed in the BNF

Answer 8

Continuation of posterior cord of the brachial plexus (root values C5 to T1) Path In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major. Enters the arm between the brachial artery and the long head of triceps (medial to humerus). Spirals around the posterior surface of the humerus in the groove for the radial nerve. At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle. At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch. Deep branch crosses the supinator to become the posterior interosseous nerve. Regions innervated Motor (main nerve) Triceps Anconeus Brachioradialis Extensor carpi radialis Motor (posterior interosseous branch) Supinator Extensor carpi ulnaris Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus and brevis Abductor pollicis longus Sensory The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger) Muscular innervation and effect of denervation Anatomical location Muscle affected Effect of paralysis Shoulder Long head of triceps Minor effects on shoulder stability in abduction Arm Triceps Loss of elbow extension Forearm Supinator Brachioradialis Extensor carpi radialis longus and brevis Weakening of supination of prone hand and elbow flexion in mid prone position Patterns of damage wrist drop sensory loss to small area between the dorsal aspect of the 1st and 2nd metacarpals Axillary damage as above paralysis of triceps

Answer 9

Basics sciatic nerve is supplied by L4-5, S1-3 divides into tibial and common peroneal nerves Supplies hamstring muscles adductor muscles Features of sciatic nerve lesion motor: paralysis of knee flexion and all movements below knee sensory: loss below knee reflexes: ankle + plantar lost, knee jerk intact Causes fracture neck of femur posterior hip dislocation trauma The common reflexes are listed below: Reflex Root Ankle S1-S2 Knee L3-L4 Biceps C5-C6 Triceps C7-C8

Answer 10

Strokes represent an important cause of morbidity and mortality. In the UK alone there are over 150,000 strokes per year, with over 1.2 million stroke survivors. Stroke is the fourth largest cause of death in the UK and kills twice as many women than breast cancer each year. The prevention and treatment of strokes has undergone significant changes over the past decade. What was previously considered a devastating but untreatable condition is now viewed more as a 'brain attack', a condition which requires emergency assessment to see if patients may benefit from new treatments such as thrombolysis. Pathological specimen showing the results of an ischaemic stroke to the occipito-parietal region of the cerebrum. Note there has been some secondary haemorrhage in the affected area. What is a stroke? A stroke (also known as cerebrovascular accident,CVA) represents a sudden interruption in the vascular supply of the brain. Remember that neural tissue is completely dependent on aerobic metabolism so any problem with oxygen supply can quickly lead to irreversible damage. There are two main types of strokes: ischaemic: these can be further subdivided between into episodes which last greater than 24 hours (termed an ischaemic stroke) and episodes where symptoms and signs last less than 24 hours (transient ischaemic attacks, TIAs, sometimes termed 'mini-strokes' by patients) haemorrhagic Symptoms and signs Stroke is defined by the World Health Organization as a clinical syndrome consisting of 'rapidly developing clinical signs of focal (at times global) disturbance of cerebral function, lasting more than 24 hours or leading to death with no apparent cause other than that of vascular origin'. In contrast, with a TIA the symptoms and signs resolve within 24 hours. Features include: motor weakness speech problems (dysphasia) swallowing problems visual field defects (homonymous hemianopia) balance problems Cerebral hemisphere infarcts may have the following symptoms: contralateral hemiplegia: initially flaccid then spastic contralateral sensory loss homonymous hemianopia dysphasia Brainstem infarction may result in more severe symptoms including quadriplegia and lock-in-syndrome Lacunar infarcts small infarcts around the basal ganglia, internal capsule, thalamus and pons this may result in pure motor, pure sensory, mixed motor and sensory signs or ataxia An example of a lacunar infarct affecting the internal capsule. One formal classification system that is sometimes used is the Oxford Stroke Classification (also known as the Bamford Classification), whichclassifies strokes based on the initial symptoms. A summary is as follows: The following criteria should be assessed: 1. unilateral hemiparesis and/or hemisensory loss of the face, arm & leg 2. homonymous hemianopia 3. higher cognitive dysfunction e.g. dysphasia

Answer 11

Urgent neuroimaging classifies the stroke as either ischaemic or haemorrhagic. If the stroke is ischaemic, and certain criteria are met, the patient should be offered thrombolysis. Example criteria include: patients present with 4.5 hours of onset of stroke symptoms the patient has not had a previous intracranial haemorrhage, uncontrolled hypertension, pregnant etc Once haemorrhagic stroke has been excluded patients should be given aspirin 300mg as soon as possible and antiplatelet therapy should be continued. Transient ischaemic attacks Remember with TIAs the, by definition, symptoms last less than 24 hours although in the vast majority of cases the duration is much shorter, typically 1 hour or so. For this reason most patients symptoms will have resolved before they see a doctor. The ABCD2 prognostic score has previously been used to risk stratify patients who present with a suspected TIA. However, data from studies have suggested it performs poorly and it is therefore no longer recommended by NICE Clinical Knowledge Summaries. Instead, NICE recommend: Immediate antithrombotic therapy: give aspirin 300 mg immediately, unless contraindicated e.g. the patient has a bleeding disorder or is taking an anticoagulant (needs immediate admission for imaging to exclude a haemorrhage) If the patient has had more than 1 TIA ('crescendo TIA') or has a suspected cardioembolic source or severe carotid stenosis: discuss the need for admission or observation urgently with a stroke specialist If the patient has had a suspected TIA in the last 7 days: arrange urgent assessment (within 24 hours) by a specialist stroke physician If the patient has had a suspected TIA which occurred more than a week previously: refer for specialist assessment as soon as possible within 7 days Haemorrhagic strokes If imaging confirms a haemorrhagic stroke neurosurgical consultation should be considered for advice on further management. The vast majority of patients however are not suitable for surgical intervention. Management is therefore supportive as per haemorrhagic stroke. Anticoagulants (e.g. warfarin) and antithrombotic medications (e.g. clopidogrel) should be stopped to minimise further bleeding. If a patient is anticoagulated this should be reversed as quickly as possible. Trials have shown improved outcomes in patients who have their blood pressure lowered acutely and this is now part of many protocols for haemorrhagic strokes. A 69-year-old gentleman presents to the emergency department with sudden onset right-sided numbness, with no other symptoms. He has a background of poorly controlled hypertension and diabetes mellitus. A CT head was arranged which reported no haemorrhage or mass. He is diagnosed as having had a lacunar stroke.

Answer 12

The original definition of a transient ischaemic attack (TIA) was time-based: a sudden onset of a focal neurologic symptom and/or sign lasting less than 24 hours, brought on by a transient decrease in blood flow. However, this has now changed as it is recognised that even short periods of ischaemia can result in pathological changes to the brain. Therefore, a new 'tissue-based' definition is now used: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction. Patients often use the term 'mini-stroke' for TIAs. Assessment and referral The ABCD2 prognostic score has previously been used to risk stratify patients who present with a suspected TIA. However, data from studies have suggested it performs poorly and it is therefore no longer recommended by NICE Clinical Knowledge Summaries. Instead, NICE recommend: Immediate antithrombotic therapy: give aspirin 300 mg immediately, unless 1. the patient has a bleeding disorder or is taking an anticoagulant (needs immediate admission for imaging to exclude a haemorrhage) 2. the patient is already taking low-dose aspirin regularly: continue the current dose of aspirin until reviewed by a specialist 3. Aspirin is contraindicated: discuss management urgently with the specialist team If the patient has had more than 1 TIA ('crescendo TIA') or has a suspected cardioembolic source or severe carotid stenosis: discuss the need for admission or observation urgently with a stroke specialist If the patient has had a suspected TIA in the last 7 days: arrange urgent assessment (within 24 hours) by a specialist stroke physician If the patient has had a suspected TIA which occurred more than a week previously: refer for specialist assessment as soon as possible within 7 days Advise the person not to drive until they have been seen by a specialist. Further management Antithrombotic therapy clopidogrel is recommended first-line (as for patients who've had a stroke) aspirin + dipyridamole should be given to patients who cannot tolerate clopidogrel these recommendations follow the 2012 Royal College of Physicians National clinical guideline for stroke. Please see the link for more details (section 5.5) these guidelines may change following the CHANCE study (NEJM 2013;369:11). This study looked at giving high-risk TIA patients aspirin + clopidogrel for the first 90 days compared to aspirin alone. 11.7% of aspirin only patients had a stroke over 90 days compared to 8.2% of dual antiplatelet patients With regards to carotid artery endarterectomy: recommend if patient has suffered stroke or TIA in the carotid territory and are not severely disabled should only be considered if carotid stenosis \> 70% according ECST\* criteria or \> 50% according to NASCET\*\* criteria \*European Carotid Surgery Trialists' Collaborative Group \*\*North American Symptomatic Carotid Endarterectomy Trial Antiplatelets TIA: clopidogrel ischaemic stroke: clopidogrel Importance: 80 Carotid artery endarterectomy is recommend if the patient has suffered a stroke or TIA in the carotid territory and is not severely disabled. It should only be considered if the carotid stenosis is greater than 70% or 50%, depending on the reporting criteria used - please see below. NICE Clinical Knowledge Summaries state the following: Antiplatelet therapy is initiated by secondary care on diagnosis of ischaemic stroke or TIA without paroxysmal or permanent atrial fibrillation for long-term vascular prevention: The standard treatment is clopidogrel 75mg daily (licenced for use in ischaemic stroke, off-label use in TIA). Modified-release dipyridamole 200 mg twice daily may be used if both clopidogrel and aspirin are contraindicated or cannot be tolerated. Aspirin 75mg daily may be used if both clopidogrel and modified-release dipyridamole are contraindicated or cannot be tolerated. Aspirin 75 mg daily with modified-release dipyridamole 200 mg twice daily may be used if clopidogrel cannot be tolerated. The 2012 Royal College of Physicians National clinical guidelines for stroke now recommend using clopidogrel following a TIA. This brings it in line with current stroke guidance.

Answer 13

Trigeminal neuralgia is a pain syndrome characterised by severe unilateral pain. The vast majority of cases are idiopathic but compression of the trigeminal roots by tumours or vascular problems may occur. The International Headache Society defines trigeminal neuralgia as: a unilateral disorder characterised by brief electric shock-like pains, abrupt in onset and termination, limited to one or more divisions of the trigeminal nerve the pain is commonly evoked by light touch, including washing, shaving, smoking, talking, and brushing the teeth (trigger factors), and frequently occurs spontaneously small areas in the nasolabial fold or chin may be particularly susceptible to the precipitation of pain (trigger areas) the pains usually remit for variable periods NICE Clinical Knowledge Summaries list the following as red flag symptoms and signs suggesting a serious underlying cause: Sensory changes Deafness or other ear problems History of skin or oral lesions that could spread perineurally Pain only in the ophthalmic division of the trigeminal nerve (eye socket, forehead, and nose), or bilaterally Optic neuritis A family history of multiple sclerosis Age of onset before 40 years Management carbamazepine is first-line failure to respond to treatment or atypical features (e.g. \< 50 years old) should prompt referral to neurology This woman has symptoms typical of trigeminal neuralgia. The first line treatment for this is carbamazepine, which should be started at 100 mg twice daily and slowly titrated up until pain is relieved.

Answer 14

Tuberous sclerosis (TS) is a genetic condition of autosomal dominant inheritance. Like neurofibromatosis, the majority of features seen in TS are neurocutaneous. Cutaneous features depigmented 'ash-leaf' spots which fluoresce under UV light roughened patches of skin over lumbar spine (Shagreen patches) adenoma sebaceum (angiofibromas): butterfly distribution over nose fibromata beneath nails (subungual fibromata) café-au-lait spots\* may be seen Neurological features developmental delay epilepsy (infantile spasms or partial) intellectual impairment Also retinal hamartomas: dense white areas on retina (phakomata) rhabdomyomas of the heart gliomatous changes can occur in the brain lesions polycystic kidneys, renal angiomyolipomata lymphangioleiomyomatosis: multiple lung cysts

Answer 15

Overview arises from medial cord of brachial plexus (C8, T1) Motor to medial two lumbricals aDductor pollicis interossei hypothenar muscles: abductor digiti minimi, flexor digiti minimi flexor carpi ulnaris Sensory to medial 1 1/2 fingers (palmar and dorsal aspects) Path the ulnar nerve travels through the posteromedial aspect of the upper arm to the flexor compartment of the forearm it then enters the palm of the hand via the Guyon's canal, superficial to the flexor retinaculum and lateral to the pisiform bone

Answer 16

The main points for the exam are: left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior) incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex A congruous defect simply means complete or symmetrical visual field loss and conversely an incongruous defect is incomplete or asymmetric. Please see the link for an excellent diagram. Homonymous hemianopia incongruous defects: lesion of optic tract congruous defects: lesion of optic radiation or occipital cortex macula sparing: lesion of occipital cortex Homonymous quadrantanopias\* superior: lesion of temporal lobe inferior: lesion of parietal lobe mnemonic = PITS (Parietal-Inferior, Temporal-Superior) Bitemporal hemianopia lesion of optic chiasm upper quadrant defect \> lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour lower quadrant defect \> upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma \*this is very much the 'exam answer'. Actual studies suggest that the majority of quadrantanopias are caused by occipital lobe lesions. Please see the link for more details.

Answer 17

Wernicke's encephalopathy is a neuropsychiatric disorder caused by thiamine deficiency which is most commonly seen in alcoholics. Rarer causes include: persistent vomiting, stomach cancer, dietary deficiency. A classic triad of ophthalmoplegia/nystagmus, ataxia and confusion may occur. In Wernicke's encephalopathy petechial haemorrhages occur in a variety of structures in the brain including the mamillary bodies and ventricle walls Features nystagmus (the most common ocular sign) ophthalmoplegia ataxia confusion, altered GCS peripheral sensory neuropathy Investigations decreased red cell transketolase MRI Treatment is with urgent replacement of thiamine Relationship with Korsakoff syndrome If not treated Korsakoff's syndrome may develop as well. This is termed Wernicke-Korsakoff syndrome and is characterised by the addition of antero- and retrograde amnesia and confabulation in addition to the above symptoms.