neuro Flashcards
parkinsons plus
PSP MSA Lew body dementia Vascular parkinsons Cortico basal degenration
PD vs Parkinson plus
PD - symmetrical
Parksinsons plus - swallowing difficulties, change in personlity, vertical gaze palsy (unable to look down)
PSP
posturnal instbaility truncal rigidity frequent falls asymetrical onset speech and swallow palsy
Multisystem atrophy
Atonomic features
Postural instability
bladder/bowel dysfunction
cerebellar/pyramidal signs
Vascular parkinsons
Parkinson’s worse in legs than in arms
vascular risk factors
CJD
rapid cognitive decline in a young person with myoclonus
EEG in sporadic CJD may show significant abnormalities involving deep brain areas such as the thalami. The normal rhythms are gradually lost. Initially the changes are diffuse, and non-specific, developing into generalised bi- or triphasic periodic sharp wave complexes with a frequency of 1-2 per second. High voltage sharp waves may be synchronous with myoclonic jerks. In an appropriate clinical context, this EEG pattern is strongly suggestive of a diagnosis of CJD.
Brain stem death tests
Brain stem death tests include:
Pupillary light response - CN II and III
Corneal reflex, response to supraorbital pressure - CN V and VII
Vestibulo-ocular reflex - CN III and VIII
Gag reflex - CN IX and X
Cough reflex - CN X
Absence of respiratory effort.
Transient global amnesia
Most attacks last one to eight hours with a mean duration of 4.2 hours. Patients are disoriented to time and place with 60% to 90% exhibiting repetitive questioning, “Where am I?” which may last throughout the attack.
anterograde amnesia, with no clouding of consciousness or loss of personal identity.
Cognitive impairment is limited to amnesia, with no apraxia or aphasia. There is no recent history of head trauma, no history of seizures in the preceding two years.
carotid endarctectomy
Carotid endartectomy is only indicated if there is >50% in some centres or else >70% stenosis of the symptomatic carotid artery. (Note the external carotid artery supplies the neck, face and skull and the 90% stenosis there is not responsible for the symptoms in this patient).
vasculaf dementia
Vascular dementia tends to cause a step-wise deterioration in cognition, and one would expect a history or findings of previous cerebrovascular disease.
Picks disease
Pick’s disease is a rare form of dementia characterised by degeneration of the frontal and temporal lobes.
Presentations are of frontal or temporal lobe syndromes, depending on the location of maximal lobar atrophy. Patients with frontal atrophy present with early personality change.
Predominant temporal lobe atrophy is associated with aphasia and semantic memory impairment.
Pathologically, Pick’s disease is associated with Pick bodies which are argyrophilic inclusion bodies within the neuronal cytoplasm.
EEG is relatively normal by contrast to Alzheimer’s disease.
Neuroleptic malignant syndrome
The diagnosis is neuroleptic malignant syndrome (NMS) which can occur at any time during the treatment with antipsychotic medications.
Concomitant treatment with lithium or anticholinergics may increase the risk of NMS.
It is manifested by:
Fever
Rigidity
Altered mental status
Autonomic dysfunction, and
Elevated creatine phosphokinase concentration.
The creatine phosphokinase concentration is always elevated (>1000 IU/L−1), reflecting myonecrosis secondary to intense muscle contracture.1
Treatment includes withdrawal of the offending agent and reduction of body temperature with antipyretics.
Dantrolene, bromocriptine or levodopa preparations may be beneficial.
cerebellar syndrome
The presence of anti-Hu antibody (a type of antineuronal antibody) supports a diagnosis a paraneoplastic syndrome.
Subacute cerebellum syndrome is one of the commonest paraneoplastic syndromes. It is usually associated with small cell lung carcinoma, breast and ovarian cancer.
CT chest, abdomen and pelvis and mammogram are required to look for a primary neoplasm.
A whole body positron emission tomography (PET) scan is preferabl
Myasthenia gravis
myasthenia gravis presenting with ocular, bulbar and limb weakness.
Late onset myasthenia gravis is associated with thymic atrophy as opposed to thymic hyperplasia.
Forty percent of seronegative patients have an antibody found to postsynaptic protein muscle-specific kinase (MuSK).
Management:
1) pyridostigmine 60 mg QDS
2) if not responding then steroids, low dose
3) respiratory weakness/crisis - IV immunoglobulins or plasmapharesis
hemiballismus
hemiballismus; the lesion is in the contralateral subthalamic nucleus.
Tetrabenezine
hemiballismus
hemiballismus; the lesion is in the contralateral subthalamic nucleus.
Tetrabenezine
Syringomyelia
cervical cord would cause lower motor neurone signs at the level of the syrinx, with dissociated pain and temperature loss and upper motor neurone signs in the legs.
Botulism
Botulism occurs either from gut colonisation (e.g., ingestion of contaminated home-canned food) or an infected wound.
Clostridium botulinum spores are widespread in soil and aquatic sediment.
Typical initial features include:
Diplopia Ptosis Facial weakness Dysarthria, and Dysphagia. Later, respiratory difficulty and limb weakness occur.
Neuromuscular blockade causes the clinical features.
In botulism, the impaired cholinergic transmission also involves autonomic synapses, causing poorly reactive dilated pupils, dry mouth, paralytic ileus and occasionally bradycardia. Reflexes are depressed or absent, sensation is normal and cerebrospinal fluid (CSF) is normal in botulism.
SDH
Subdural haematomas are as a result of blood within the outermost meningeal layer between the dura and arachnoid mater and results from tearing of the bridging veins.
Extradural haemorrhage
Tearing of the middle meningeal artery results in an extradural haematoma.
SAH
Rupture of the anterior and posterior communicating arteries results in subarachnoid haemorrhage.
IIH
IIH typically affects young obese women.
Other risk factors include:
The oral contraceptive pill
Treatments for acne (tetracycline, nitrofurantoin, retinoids), and
Hypervitaminosis A.
Presentation is with a headache, which may be severe. There may be loss of peripheral vision and impaired visual acuity if papilloedema is severe. Reduction in colour vision is common and a significant number of patients develop a CN VI palsy.
CT scan is often normal; the diagnosis is confirmed by finding an elevated cerebrospinal fluid (CSF) opening pressure (more than 20 cmH2O). CSF protein, glucose and cell count will be normal.
The differential diagnosis includes venous sinus thrombosis; increased use of MRI has shown that small thromboses are commoner than previously thought in these patients.
MRI and/or MRI venography is essential in these patients.
neuralgic amyotrophy
proceeded by an upper respiratory tract infection.
Pain around the shoulder is the presenting symptom that is usually very severe.
As the pain starts resolving, weakness begins and usually affects the muscles innervated by the upper brachial plexus (C5-6).
Treatment is conservative. It is usually a self-limiting condition (improvement over weeks to months).
There have been several cases of elevated cerebrospinal fluid protein with neuralgic amyotrophy.
vertebrobasilar insufficiency
short episodes lasting minutes of loss of consciousness associated with brainstem features (diplopia, dysarthria and dizziness).
They are not posturally related, and on some occasions have been associated with reflex anoxic seizures.
There does not appear to be any history of confusion following these attacks or any precipitating factors. Hyperextension of the neck however can precipitate loss of consciousness, which may have occurred in the hairdressers.
everal vascular risk factors including hypertension, hypercholesterolaemia and probable glucose intolerance
HSV encephalitis
HSV encephalitis which presents with fever, headache, vomiting, behavioural changes, confusion and seizures. MRI classically shows high signal in the temporal lobes.
LIsteria meningitis
Listeria meningitis affects immunosuppressed patients or patients at extremes of age. It can present with reduced conscious level, seizures and cranial nerve palsies
Meningococcal meningitis
Meningococcal meningitis presents with headache, neck stiffness, photophobia, vomiting and fever.
SAH
Subarachnoid haemorrhage classically presents with a thunderclap headache and neck stiffness
TB meningitis
TB meningitis presents gradually with headache, neck stiffness, photophobia, vomiting and fever. It occurs more commonly in those who are immunosuppressed, for example secondary to AIDS.
Anterior ischaemic optic neuropathy
Anterior ischaemic optic neuropathy causes persistent monocular visual loss associated with a relative afferent pupillary defect and is the most common cause in patients over the age of 50 years. There is normally a background of hypertension and diabetes.
antiphospholipid syndrome
Cerebral venous thrombosis
pulmonary hypertension with right heart strain, mild anaemia and thrombocytopenia with a prolonged activated partial thromboplastin time. The likely cause of the venous sinus thrombosis is anti-phospholipid syndrome leading to a hypercoaguable state.
Cerebral amyloid angiopathy
Cerebral amyloid angiopathy (CAA) would cause haemorrhagic strokes but would not explain the right heart strain.
ALS MND
The initial clinical manifestation of ALS may occur in any body segment (bulbar, cervical, thoracic or lumbosacral) and may manifest as upper motor neuron or lower motor neuron symptoms or signs. Twenty percent of patients will have onset in the bulbar segment, which most often presents with either dysarthria or dysphagia.
pituitary apoplexy
headache sudden onset
cavernous sinus compression (i.e. third and fifth nerve palsy
compression of the chiasm as suggested by the bitemporal hemianopia
expanding mass can compress the cavernous sinus with the Ocular nerves and the trigeminal nerve
SIADH due to tumor
anterior artery communicating aneurysms
anterior artery communicating aneurysms are asymptomatic unless they rupture, and so they are usually found either incidentally or when a patient presents with SAH. Some unruptured aneurysms can become symptomatic. Symptoms include headache (which may be severe and comparable to the headache of SAH), visual acuity loss, cranial neuropathies (particularly third nerve palsy), pyramidal tract dysfunction, and facial pain; they are felt to be due to the mass effect of the aneurysm.
Wallenberg’s syndrome,
Wallenberg’s syndrome, or lateral medullary syndrome, is due to infarction of the posterior inferior cerebellar artery resulting in ipsilateral V, IX, X nerve involvement, dissociated sensory loss and ataxia.
Weber’s syndrome
Weber’s syndrome is a mid brain stroke with ipsilateral third nerve palsy and contralateral hemiplegia.
VHL
bilateral cerebellar haemangiomas, which have led to compression of the fourth ventricle, and hydrocephalus manifested by headache, papilloedema and vomiting
renal cell carcinoma with secondary polycythaemia, as evidenced by right flank mass, haematuria
haemangioblastomas of the central nervous system (CNS) or retina, and the presence of one associated VHL tumour (renal cell carcinoma, islet cell tumours and adenomas)
Occlusion of the anterior cerebral artery
Occlusion of the anterior cerebral artery is rare and can cause transient incontinence, motor and sensory disturbance affecting the leg more than the arm and a transcortical aphasia.
Occlusion of basilar artery
Occlusion of basilar artery, posterior cerebral artery and vertebral arteries produces signs and symptoms of posterior and brainstem circulation syndromes.
craniopharyngioma
craniopharyngioma compressing the chiasm from above leading to a bilateral inferior quadrantinopia.
some cavernous sinus extension given the trigeminal nerve involvement and also compression of the pituitary stalk, leading to overproduction of prolactin
pituitary visual field defect
A pituitary adenoma is more likely to cause a superior bitemporal field defect initially, and one might expect to see signs or symptoms of pituitary dysfunction.
fridrivhs ataxia
Friedreich’s ataxia is an autosomal recessive condition normally presenting within the first decade. The posterior columns, corticospinal and spinocerebellar tracts are affected leading to cerebellum dysfunction, spastic paraparesis and absent reflexes in lower limbs.
There is also myocardial muscle involvement leading to hypertrophy and heart failure. Bilateral pes cavus and kyphoscoliosis are common and some patients develop diabetes and optic atrophy.
Foster Kennedy syndrome
Foster Kennedy syndrome as a result of olfactory meningioma with optic nerve involvement. The presence of optic atrophy on one side with contralateral papilloedema is characteristic of Foster Kennedy syndrome as it is usually due to frontal tumour or tumour within the olfactory bulb compressing the ipsilateral optic nerve and causing raised intracranial pressure.
anterior ischaemic optic neuropathy
An anterior ischaemic optic neuropathy secondary to atherosclerosis or temporal arteritis would cause acute monocular visual loss associated with headache.
jacksonian seizure
A jacksonian seizure is also known as a focal (partial) motor seizure. In this condition an uncontrolled, spontaneous discharge of electricity from one motor cortex presents with contralateral motor signs. The patient has preserved consciousness as it is a partial seizure and after the seizure it is common to have a Todd’s paralysis where the limb is weak.
Tuberous sclerosis
CT scan shows evidence of calcified phakomas in the periventricular white matter.
Combined with the clinical findings of spastic weakness and skin stigmata, and history of epilepsy with learning difficulties, the likely diagnosis is tuberous sclerosis. This condition can occur both spontaneously or is inherited in an autosomal dominant form.
Characteristic findings include:
Adenoma sebaceum
Learning difficulties, and
Seizures.
In addition patients can also have:
Retinal hamartomas
Shagreen patches
Ungual fibromas, and
Rhabdomyomas of the heart.
multifocal motor neuropathy (MMN).
marked asymmetrical lower motor neurone weakness affecting the right arm/forearm, in absence of sensory findings, with weakness disproportionate to the degree of wasting.
MMN is an autoimmune neuropathy associated in 80% of cases with an elevated anti-GM1 ganglioside antibody and typically presents with progressive weakness affecting an isolated limb without sensory involvement
Treatment with IV immunoglobulin may be very effective in some patients. Cyclophosphamide is also used on a long term basis..
Juvenile myoclonic epilepsy
Juvenile myoclonic epilepsy is the commonest of the idiopathic generalised epilepsies.
Seizures types include:
Absences
Myoclonic jerks and
Tonic-clonic seizures which tend to occur within an hour of waking.
Precipitating factors include alcohol, menstruation and sleep deprivation.
Lambert Eaton syndrome
This is a paraneoplastic disorder usually associated with small cell lung carcinoma. It is a presynaptic neuromuscular disorder associated with decreased release of acetylcholine from the presynaptic cleft. It is associated with positive voltage-gated calcium channel antibodies.
Clinical features include:
autonomic symptoms
proximal lower limb weakness
reduced reflexes, and
mild ptosis.
serotonin syndrome
Serotonin toxicity leads to changes in mental status, systemic changes and motor complications.
Changes in mental status include:
confusion agitation hypomania anxiety, and coma. Systemic changes include:
tachycardia hypertension nausea salivation, and Pyrexia. Motor complications include:
myoclonus hyper-reflexia seizures in-coordination, and tremor. Muscle rigidity can occur but is more likely in neuroleptic malignant syndrome.
Treatment is supportive and involves removing the precipitating drugs, controlling agitation, administering serotonin antagonists (cyproheptadine or methysergide) and controlling hyperthermia.
Dantrolene is a drug used in neuroleptic malignant syndrome for controlling muscle rigidity which is not present in this patient.
difference between serotonin syndrome and NMS
NMS develops over days to weeks, whereas serotonin syndrome develops over 24 hours. Serotonin syndrome is characterized by neuromuscular hyperreactivity (tremor, hyperreflexia, myoclonus), while NMS involves sluggish neuromuscular responses (rigidity, bradyreflexia). Hyperreflexia and myoclonus are rare in NMS.
PXE
angiod streaks
yellow papules
PXE is a rare heritable connective tissue disorder with autosomal dominant and recessive modes of inheritance. It involves the elastic tissues of the eye, skin and cardiovascular system.
Visual loss can occur by infarction of the visual pathways and is likely to explain the chronic changes of optic disc atrophy in this patient.
Cerebral ischaemia in PXE is caused by small vessel occlusive disease.
Other neurological complications include:
Intracranial aneurysms Subarachnoid and intracerebral haemorrhages Progressive intellectual deterioration Mental disturbances, and Seizures.
anion gap methanol toxicity
methanol toxicity.
Early signs of toxicity are due to methanol. Later signs are due to its metabolite, formic acid.
Early signs include:
Nausea Vomiting Headache, and Confusion. Formic acid later produces a metabolic acidosis and retinal injury.
The laboratory data show a high gap metabolic acidosis.
Anion gap = (Na + K) − (Cl + HCO3); normal range 7-17 mmol/L.
Although elevated, the lactate level does not account for the anion gap. The diagnosis can be made early by measuring the serum methanol and serum formate levels.
Treatment is aimed at:
Eliminating formic acid (alkaline diuresis or haemodialysis).
Correcting acidosis with IV bicarbonate.
Preventing metabolism of methanol to formic acid by administering IV ethanol.
Sydenham’s chorea.
acute chorea as a result of streptococcal throat infection or Sydenham’s chorea.
This tends to occur in children presenting initially with irritability and inattentiveness. This then progresses to generalised chorea with speech involvement occurring in 20% of cases. Those who have had several attacks in childhood may develop chorea in adulthood when exposed to drugs such as the oral contraceptive pill, phenytoin or digoxin, or during pregnancy.
Treatment is for chorea with tetrabenazine or sulpiride and a course of penicillin for acute infection.
carotid-cavernous fistula
would cause acute painful, pulsating exophthalmos, in addition to visual loss and diplopia.
seizure of unknown aetiology
EEG
MRI/CT head
r/o struvtural cause e.g AVM
botulism
clostridium
The clinical presentation of descending weakness with autonomic dysfunction (fixed dilated pupils) is typical of botulism.
It is a neuromuscular junction disorder and therefore nerve conduction studies and EMG are normal.
Repetitive nerve stimulation shows incremental responses, which is diagnostic of botulism.
Cerebrospinal fluid analysis is usually normal
selective serotonin reuptake inhibitor (SSRI) discontinuation syndrome
selective serotonin reuptake inhibitor (SSRI) discontinuation syndrome which typically occurs following abrupt withdrawal of SSRIs.
Symptoms can occur within days and can last months following withdrawal and then disappear.
A combination of the following symptoms can develop:
Psychiatric (anxiety, insomnia, mood lability, vivid dreams)
Gastrointestinal (nausea, vomiting), and
Neurological (dizziness, headache, paraesthesia, dystonia, tremor).
It is thought that shorter acting SSRIs, when discontinued or when the dosage is lowered, produce an “anticholinergic rebound,” interrupting the production of the acetylcholine.
No specific treatment is given.
Korsakoff’s syndrome is associated with heavy alcohol use and is characterised by amnesia and confabulation with lack of ability to reason.
recent onset of memory difficulties, mild impairment of attention and concentration and the lack of ability to reason would be more in keeping with Korsakoff’s amnesic syndrome
retained features of acute Wernicke’s encephalopathy, in particular ataxia and nystagmus, add support to the diagnosis of Korsakoff’s amnesic syndrome.
Thiamine is given in established cases to prevent progression of deficits.
