Neurology

Question 1

How do you interpret the level of CK in investigation of myopathies?

Answer 1

High: 200-300 x normal dystrophin loathes
Intermediate: 20-30 x normal inflammatory myopathy
Low: 2-5 x normal neurogenic disorder

Question 2

Mononeuritis multiplex?

Answer 2

Simultaneous or sequential involvement of non contiguous nerve trunks in a peripheral neuropathy. Often from vasculitis causing impaired blood supply via vasa nervorum

Question 3

What kind of peripheral neuropathy is diabetic?

Answer 3

Mostly axonal, but with varying degrees of demyelination

Question 4

Demyelinating polyneuropathies?

Answer 4

Monoclonal gammopathies
Autoimmune eg guillian barre
N-hexane exposure
Paraneoplastic
POEMS syndrome
Anti-MAG antibodies
Charcot Marie Tooth - 1A, 1B and X linked ( but some axonal )
NGUS and para protein

Question 5

Axonal polyneuropathies?

Answer 5

HIV
Lyme disease
Amyloidosis
Thyroid disease
GB syndrome-AMAN variant: acute motor axonal neuropathy
Critical illness associated polyneuropathy
B12/folate deficiencies
Toxins:chemotherapy, alcohol, heavy metals
Charcot Marie Tooth type 2
NARP syndrome

Question 6

What is the differential for Rapidly Progressive Dementia?

Answer 6

Vascular… coags profile, echo, carotid ultrasound, cerebral angiogram
Infectious… Viral PCR,bacterial and fungal cultures,AFB
Toxic-metabolic…24hr urine heavy metal for lead, arsenic,mercury,bismuth,aluminium,lithium. Copper and ceruloplasmin,exposure history, methylmalonic acid levels, thiamine, vit E
Autoimmune… Screen, paraneoplastic antibodies
Metastases/neoplasm…neuro imaging, PET, csf cytology and flow cytometry, serum LDH, tumour markers
Iatrogenic
Neurodegenerative eg CJD, Alzheimer’s, DLB, FTD, CBD/PSNP
Systemic

Question 7

Consider CJD in rapidly progressive dementia when….

Answer 7

There is a prominent motor or cerebellar component

Question 8

Which cancer is associated with anti-Hu antibodies?

Answer 8

small cell lung cancer

Question 9

What are the associations of anti-Ma2 antibodies? (Aka anti-Ta)

Answer 9

Testicular cancer and extra testicular germ cell tumours

Question 10

What are the associations with anti-CRMP5 encephalomyelitis?

Answer 10

SCLC and thymoma

Question 11

What are the associations with anti-NMDA receptor antibodies?

Answer 11

In female adult patients, over 50 percent have ovarian teratomas.
In male patients, a tumour is rarely found

Question 12

What are the associations with anti LGI1antibodies?

Answer 12

20 percent only have thymoma or SCLC

Question 13

What are the three Ds of pellagra (niacin deficiency) ?

Answer 13

Diarrhoea
Dermatitis
Dementia

Consider in patients with anorexia, alcoholics, and people taking isoniazid

Question 14

Vitamin B1

Answer 14

Thiamine

Note: deficiency causes beriberi

• Wernicke’s encephalopathy
• heart failure
• Korsakoff’s syndrome
• sensorimotor neuropathy

Question 15

Vitamin B2

Answer 15

Riboflavin

Deficiency causes ariboflavinosis

• cheiolosis and angular cheilitis
• photo sensitivity
• glossitis
• dermatitis

Question 16

Vitamin B3

Answer 16

Niacin

Deficiency causes pellagra

• dermatitis
• diarrhoea
• dementia
• death
• aggression
• insomnia
• weakness

Question 17

Vitamin B6

Answer 17

Pyridoxine

Question 18

Vitamin B9

Answer 18

Folic acid

Note:over supplementation masks B12 deficiency which can result in permanent neurological damage

Deficiency causes

• macrocytic anaemia
• elevated levels of homocysteine
• birth defects

Question 19

Vitamin B12

Answer 19

Cobalamin

Deficiency causes macrocytic anaemia, elevated homocysteine, peripheral neuropathy, memory loss/mania/psychosis

Question 20

Vitamin B5

Answer 20

Pantothenic acid

Deficiency causes acne and parasthesias

Question 21

Seizures in peripartum? Differential

Answer 21

Eclampsia
Reversible posterior leukoenceohalopathy- headache, seizures, confusion, visual disturbance + characteristic imaging- posterior cerebral hemisphere white matter oedema.Often hypertensive.
Venous sinus thrombosis
Other stroke
SOL
Metabolic (hypoglycaemia, uraemia,siadh)
Infection (meningitis/encephalitis)
Thrombophilia
Illicit drug use
Cerebral vasculitis
Idiopathic epilepsy

Question 22

Criteria CJD

Answer 22

Rapidly progressive dementia
+ 2 of 4 of myoclonus/visual or cerebellar signs/pyramidal or extrapyramidal signs/a kinetic mutism
+ positive lab test out of : typical EEG(periodic sharp wave complexes)/positive 14-3-3 CSF with disease duration less than 2 years/ MRI high signal abnormalities in caudate nucleus/ put amen on DWI or FLAIR

Question 23

Rapidly progressive dementia

Answer 23

CJD
Neurodegenerative (AD, mixed AD/vascular,DLB,FTD, PSP, CBD
Infection-HIV/fungal/bacterial
Vasculitis
Malignant-tumour (mets/primary/intravascular lymphoma) or paraneoplastic encephalitis, thyroid/PT disease
Endocrine-hashimotos encephalitis
Autoimmune-hashimotos, autoimmune enceph, lupus cerebritis, sarcoid
Psychiatric conditions
Heavy metal toxicity
Metabolic-thiamine or B12 def, niacin def

Question 24

Levodopa mechanism

Answer 24

Converted to dopamine in brain and peripheral tissues, replenishing depleted striatal dopamine.
Give with a peripheral decarboxylase inhibitor to reduce peripheral dopamine production and reduce adverse effects eg nausea, vomiting and hypotension
Food reduces absorption

Question 25

PDdrug brand names

Answer 25

``` Madopar= levodopa + benserazide Sinemet = levodopa + carbidopa Stalevo = levodopa+ carbidopa + entacapone Sifrol= entacapone ```

Question 26

Entacapone mechanism

Answer 26

Inhibits COMT (catechol-O-methyltransferase) mainly in peripheral tissues, increases the amount of levodopa available to the brain and prolongs clinical response to levodopa

Question 27

Pramipexole mechanism

Answer 27

Dopamine agonist- stimulates dopamine receptors. Inhibits prolactin secretion. Decreases growth hormone concentration in people with acromegaly. Watch our for pathological gambling, loads of sex etc Give domperidone before if nauseated

Question 28

Which are the non ergot derived dopamine agonists? Why are ergot ones not used any more?

Answer 28

Ergot derived are bromocriptine, cabergoline, pergolide-caused fibrosis of lungs, retroperitonium, pleura. Caused valvular incompetence, behavioural problems. Non ergot are pramipexole (po), apomorphine (subcut), ropinirole (po), and rotigotine (patch)

Question 29

Selegiline

Answer 29

Used as an adjunct to levodopa Irreversible inhibition of MAO-B (mono amine oxidase B)- reduces breakdown of dopamine and possibly blocks dopamine reuptake

Question 30

Amantadine

Answer 30

Increases dopamine release, blocks cholinergic receptors. NMDA antagonist in the glutamatergic pathway from subthalamic nucleus to globus pallidus. Also antiviral activity against some strains of flu A

Question 31

Internuclear ophthalmoplegia- weak adduction of affected eye + abduction nystagmus of contra lateral. Caused by lesion to MLF in dorsomedial brainstem tegmentum of pons or medulla

Answer 31

``` Multiple sclerosis (young patients, often bilateral) Cerebrovascular disease Infection Tumour Trauma ``` Mimics- miller-fisher variant of guillain barre, partial third palsy, myasthenia gravis PEARL- convergence is spared in INO. Distinguishes from partial third nerve palsy

Question 32

Miller fisher variant of guillain barre

Answer 32

Ophthalmoplexia, ataxia, areflexia | Autoab GQ1b

Question 33

Parietal lobe lesion (r or l) causes-

Answer 33

``` Astereognosis Agraphasthesia Visual field defect (homonymous hemianopia, inferior quadrantonopia) Sensory and visual inattention Failure of 2 point discrimination Constructional apraxia Dressing apraxia Mild hemlines left Contra lateral neglect ```

Question 34

What is the Tensilon Test?

Answer 34

Test used to distinguish between myasthenia gravis, choline rig crisis, and lambert-eaton myasthenic syndrome. Edrophonium is a reversible acetylcholinesterase inhibitor. LEMS- little if any improvement after injection because no correction of small amounts of acetylcholine release because of autoimmune attack on calcium channels P/Q type. Cholinergic crisis- weakened worsens because extra acetylcholine induces a depolarising block in the already too-stimulated junction MG- improvement for 10-30 minutes as concentration of acetylcholine increases

Question 35

Where is the lesion in hemibalismus?

Answer 35

Subthalamic nucleus

Question 36

Where is the lesion in chorea?

Answer 36

caudate (especially HIV) Also putamen, subthalamic nucleus, thalamus

Question 37

What is Adie Holmes pupil?

Answer 37

Unilateral dilated pupil that does not react to direct or consensual but does accomodate Also see loss of deep tendon reflexes and abnormal sweating, Probably due to infection and damage to ciliary ganglion Give pilocarpine to watch constrict

Question 38

What is Argyll Robertson pupils?

Answer 38

Both constricted. Accomodate but do not react Specific for neurosyphilis Can see in DM Damate to pretectal nucleus

Question 39

DBS in PD for motor fluctuations?

Answer 39

superior to best medical therapy for motor fluctuations

Question 40

MECHANISM OF TRYPTANS

Answer 40

5HT 1B/1D agonists