Neurology Flashcards
What is Gertsmann Syndrome?
When there is a lesion (stroke, tumour, etc) in the dominant angular gyrus (part of the parietal lobe), causing a constellation of acalculia (unable to do calculations), agraphia (unable understand drawing of a number on hand), L-R disorientation, and finger agnosia.
Which lobe would a lesion be if they had isolated gait apraxia?
Frontal lobe
If a patient has resurfacing of primative reflexes (pout, glabella tap, grasp), where does it suggest there is damage?
Frontal lobe
Foster Kennedy syndrome is what?
Raised intracranial pressure, optic nerve atrophy, anosmia, and personality change from a frontal lobe lesion pressing dowen on the cribiform plate
A patient presents with alexia. Where is their lesion?
Occipital lobe
Where is the lateral geniculate nucleus?
It’s in the thalamus
What is Broca’s aphasia, and where is Broca’s region?
Broca’s region is in the dominant (usually left) frontal lobe. Leads to expressive aphasia - paucity of words.
What is Wernicke’s aphasia, and were is Wernicke’s region?
Wernicke’s regions is in the dominant (usually left) temporal lobe. Receptive aphasia. Don’t understand what is being said, or really what they are saying.
What area is impacted to create a conduction aphasia?
Conduction aphasia points to a lesion impacting the arcuate fascilus which is a tract conntecting Broca’s region in the dominant frontal lobe to Wernicke’s region in the dominant temporal lobe.
What path is taken by upper motor neuron axons (cortex to spine), and where to the decussate?
The upper motor neuron cell bodies are located in the motor cortex, which is a band of the cortex at the posterior of the frontal lobe. The axons from these cells bundle together to form the central semiovale, then the corona radiata, and then the internal capsule (still in the cerebrum, getting tighter together tas the progress down towards the spinal cord). As the internal capsule travels into the midbrain is gets a different name - Crus cerebri. Then as it moves into the pons it becomes known as the ‘Basis Pontis’. Then as it reaches the medulla it becomes known as the ‘pyramids’. At the lower part of the medulla it DECUSSATES the Finally, it enters the spinal cord and becomes known as the corticospinal tract.
What path is taken by sensory neurons resonsible for pain, temperature and crude touch? Where do they synapse and where dothey decussate?
Cell bodies start in the parietal lobe, then synapse at the thalamus. Second order sensory neurons have cell bodies in the thalamus that project to through the midbrain, pons and medulla to the spinal cord ipsilaterally - spinothalamic tract. They then decussate at the spinal level nearest to the part of the body they are going to innervate and synapse with peripheral sensory nerves in the lateral aspect of the spional cord.
Is there 1 thalmus, or 2 thalamuses?
It gets called ‘the thalamus’ (singular), but it’s actually 2 mirror image structures (one for the left brain and one for the right) with symmetry across the midline. Each lobe is a concentration of nuclei that participate in modifiying processing of language, memory, motor, sensory, arousal, and visual function. There is some amount of redundancy across the lobes. So, if nuclei involved in arousal are impacted by a lesion on
the left side of the thalamus, the nuclei on the right with the same function would prevent obtundation.
What path is taken by sensory neurons responsible for proprioception, vibration and fine (discriminitive) touch? Where do they synapse and where to they decussate?
Cell bodies start in the parital lobe, axons project to the thalamus. Second order neurons project axons through the midbrain, pons and to the medulla where they decussate. Note that this is dfferent tot her spinothalamic tract which doesn’t decussate until the spinal level. The third order sensory neurons have denditic processes that extend down through the spinal cord and exit through the dorsal aspect of the spinal cord, then have a cell body in the dorsal root ganglion. The axon then projects to the tissue.
What is the role of the anterio nuclei of the thalamus?
Language and memory function
What is the role of the lateral nuclei of the thalamus?
Motor and sensory function
What is the role of the medial nuclei of the thalamus?
Arousal and memory function
What is the role of posterior (pulvinar) nuclei of the thalamus?
Visual function
Where, classically, is a lesion located if a patient presents with hemisensory loss involving the face, upper limbs and lower limbs?
In the contralateral thalamus
What are the cerebellar hemspherical signs?
Ipsilateral:limb ataxia, dysmetria, intenion tremor, dysdiadochokinesia, nystagmus
What happens if you have lesion in your cerebellar vermis? (the medial part of the cerebellar)
Trunkal ataxia and nystagmus
What are the components of the brainstem in order?
From superior to inferior: mdibrain -> pons -> medulla
Rule of 4s: what are the cranial nerve nuclei located in the midbrain?
Cranial nerves 3 and 4. Note that nerves 1 and 2 have their nuclei in the brain itself, superior to the midbrain.
Rule of 4s: what are the four structures in the midline of the brain that begins with M?
Motor pathay (corticospinal tracs), medial lemnisus (dorsol column), medial longitudinal fasciculius, and motor CN nuclei (CN 3,4, 6, 12)
Rule of 4s: what are the four structres on the sides (lateral) of the brainstem that begin with S?
Spinocerebellar pathways, spinothalamic pathways, sensory nucleus of the 5th CN, sympathetic tract
What are the bulbar signs?
Signs and symptoms suggestive of problems with cranial nerves IX, X, XI, XII. These are the 4 cranial nerves located in the medullar. The medullar looks like a tulip bulb. Therefore, these are often, in a sign of medical profession insanity, referred to as bulbar signs.
What is the role of EEG, LP and MRI head in the assessment if subacute psychosis if autoimmune encephalitis is suspected?
EEG is usually normal in inorganic psychosis. LP is vital for excluding infectious encephalitis - particularly HSV encephalitis that can be treated with acyclovir. MRI head is normal in 70% of autoimmune encephalitis, but can be helpful in excluding other causes.
What intracytoplasmic protein clusters are present in the neurons of patients with Parkinson disease?
Alpha syneuclein
What are the 3 cardinal symptoms of Parkinsons disease?
Bradykinesia, tremor, and rigidity. A fourth ifbit were to be added would be postural instability
Clinically, what are features that differentiate vascular (infarct related) parkinsons disease from idiopathic parkinsons disease?
Vascular PD classically has more negative symtpoms than positive symptoms. That is bradykinesia and rigidity, without tremor.
What classes of drugs are possible causes of drug induced parkinsons disease?
Anything that inhibits dopamine receptors may be a culprit. This includes metoclopramide and other antiemetics, antipsychotics, some opiate-like drugs.
Multiple system atrophy is a Parkinsons Plus syndrome. What are its two subtypes and their classical clinical features?
MSA-P (for parkinsonian) is the first subtype. It features symmetric parkinsonism at the onset. MSA-C (for cerebellar) is the second subtype. It features cerebellar atrophy with cerebellar syndrome. BOTH feature early and prominent autonomic dysfunction- impotence, orthostatic hypotension, constipation, urinary frequency.
Which medication is least likely to worsen parkinson features of Lewy body dementia whilst treating its psychiatric symptoms?
Clozapine is hands down the best, but quetiapine is often more practical.
What are the intracytoplasmic inclusions seen in the neurons of patients with Lewy Body Dementia?
alpha-syneuclein (also known as Lewy bodies!)
What medications are used in Lewy body dementia?
Although the parkinsonian and psychiatric symtpoms of Lewy Body Dementia are dopaminergic in nature, they classically don’t respond well to dopamine replacement therapy or therapies that increase synaptic dopamine concentration, and these medications usually worsen the patients cognitive impairment or psychiatric features. Instead antipsychotic medications (clozapine or quetiapine) and cholinesterase inhibitors (like donezapil) are used as LBD pts also develop a loss of cholinergic neurons as in seen in Alzheimers disease.
Corticobasal degeneration is a neurodegenerative disease of the Parkinsons Plus group. What are its clinical features?
It has marked usually unilateral parkinsonism and prominent apraxias. The classical feature that distinguishes CBD from PD is alien limb phenomenon- the pt believes that their limb has a mind of its own.
Progressive supranuclear palsy is a neurodegenerative disease of the Parkinsons Plus group. What are its clinical features?
Patients with PSP classically present with parkinsonism and impaired voluntary vertical gaze (supranuclear opthalmoplegia). Impaired downward gaze is the most specific clinical feature. Importantly, infranuclear (brainstem) pathways remain in tact and so dollshead vertical gaze is preserved. Typically, patients present with falls due to vision issues.
What are the Parkinson Plus syndromes?
Multiple system atrophy (symmetric parkinsonism, MSA-p/c, profound autonomic dysfunction), corticobasal degeneration (unilateral parkinsonism, alien limb), Lewy Body Dementia, Progressive supranuclear palsy (voluntary vertical gaze loss down>up, involuntary vertical gaze - ‘dollseye’ - is preserved).
What sensory symptom is most common in patients with parkinsons disease?
Anosima- in 80-100% of patients.
What symptom of Parkinson disease best correlates with percentage of dopaminergic neurons lost in the substantia nigra?
Bradykinesia. Tremor correlates very poorly.
When considering a diagnosis of Parkinsons disease, what symptoms or signs should be considered a red flag suggestive of a possible alternative diagnosis?
Rapidly progressing dementia (lewy body dementia), rapidly progressive course (more likely a parkinsons plus), suspranuclear gaze palsy (PSP), upper motor neurons signs (stroke), cerebellar symptoms (MSA-c), urinary incontinence (MSA or lewy body dementia), early symptomatic postural hypotension within 5 years (MSA), early falls (MSA or PSP).
What is the point of carbidopa when combined with levodopa?
L-dopa is a form of dopamine that crosses the blood brain barrier and can be taken orally. Normally however, l-dopa would be enzymatically degraded in the gut by aromatic-amino acid decarboxylases. Carbidopa inhibits these enzymes prolonging increasing the amount of L-dopa absorbed. COMT inhibitors such as entacapone can be used with a similar role, as COMT degrades L-dopa peripherally.
What is the role of amantidine in Parkinsons disease?
Aids in the treatment of tremor, but is most helpful in alleviating the symptoms of levodopa induced dyskinesias.
What is the major contraindication for deep brain stimulator insertion in patients with parkinson disease?
Cognitive impairment. Worsening cognitive function was reported with the insertion of deep brain stimulators.
Rasageline and selegiline are a first line treatment option for mild-moderate parkinsons disease in patients under 75. How do they work and what is their concerning side effect?
Monoamine oxidise B inhibitors (MAO-B). They work by impairing the synaptic breakdown of dopamine and other monoamine neutransmitters thus increasing their synaptic concentration and mitigating parkinsonism associated with dopamine deficiency.
Autodomal dominant cerebellar ataxia/spinocerebellar ataxia is genetic disease caused by what type of gene mutation?
CAG repeats of various lengths in SAC genes.
Where is Brocas area?
Frontal lobe of dominent hemisphere.
What are the the features of dominent parietal lobe defects?
Agraphia, acalculia, finger angosia, left/right descrimination failure
What are the features of an internal capsular infarct?
Contralateral face, arm and leg weakness. Upper motor neuron signs including spacticity, hyperreflexia. No cortical signs.
What areas are involved in a dysarthria and clummsy hand syndrome?
Lacunar stroke - can involve internal capsule or anterior part of contralateral pons.
Ataxia hemiparesis is a lacunar syndrome. Where is the infarct?
Corona radiata, pons or internal capsule.
In the brainstem, do the motor tracts travel laterally or medially?
Medially!
Where does the medial longitudinal fasciculous run?
Fromt he pons to the midbrain, medially! Part of medial brainstem stroke syndromes causing INOs.
What’s a good way of remembering which cranial nerves are lateral, and which nerves are medial?
If the cranial nerve number divides into twelve, then its medial. If it doesn’t, it’s lateral.
What classically leads to a homonymous hemianopia with macular sparing?
Occipatal infarct from a P1 branch cva
Where do the motor fibres decussate in the brainstem?
The medullar
If you have a medullary syndrome with a horners on the right, what does this tell you?
It tells you the lesion is on the right. If given a question that is clearly a lateral medullary syndrome with a horner’s syndrome, then use the side of the horner’s to tell you the side of the lesion.
What is a key difference between a conus medullaris and cauda equine?
Conus medullaris is a central upper motor neuron phenomenon. More defined areas of sensation loss. Erectile dysfunction is a feature. Minimal pain - but critically - Up going plantars!
What does C5 do at each joint?
Abducts shoulders, flexes elbow, allows supination of forearm.
What does C6 do with regards to joint movement?
Elbow extension AND flexion, and wrist extension.
C7 does what with regards to joint movements?
Moves the wrist and extends the elbow.
What does C8 do over the joints?
Flexes and extends the fingers.
Where is the dermatome for C7?
Middle finger
What nerve roots are involved in the triceps reflex?
C7/8
What is the classic feature of an axillary nerve palsy?
Deltoid weakness and patch of numbness over the shoulder
What determines the amount of clawing seen in an ulnar claw?
How distal the lesion is. More distal, more clawing.
Whatas the differnece beteween a femoral nerve and an L2 nerve problem?
Knee movement is preserved in L2 issues. Femoral nerve impairs hip and knee, L2 just imparis the hip.
What roots are involved in each trunk of the brachial plexus?
C5-6 (upper trunk), C7 (middle trunk), C8/T1 (lower trunk)
What innervates the lateral thigh, and what innervates the medial thigh?
Lateral cutaneous nerve of the thigh does lateral, femoral nerve does medial.
How do you differntiate between a femoral nerve palsy and an L3 nerve palsy?
L3 root problem causes issues hip adduction. Femoral nerves do not.
L5 has actions across many joints. However, it has one critical action that helps differentiate it from peripheral nerve problems. What it is?
Dorsiflexion of the great toe.
Which nerve roots control inversion and eversion of the ankle?
Inversion is controlled by L4/5, and everions is L5/S1
