Neurology V Flashcards
(25 cards)
SCD occurs because of B12 deficiency affecting which affected columns? [3]
dorsal column involvement, lateral corticospinal tracts and spinocerebellar tracts of the spinal cord
Spinocerebellar; Corticospinal and Dorsal column
Describe the clinical features of SCD [3+]
dorsal column involvement
* distal tingling/burning/sensory loss is symmetrical and tends to affect the legs more than the arms
* impaired proprioception and vibration sense
lateral corticospinal tract involvement:
* muscle weakness, hyperreflexia, and spasticity
* upper motor neuron signs typically develop in the legs first
* brisk knee reflexes
* absent ankle jerks
* extensor plantars
spinocerebellar tract involvement
* sensory ataxia → gait abnormalities
* positive Romberg’s sign
Descrirbe what is Syringomyelia (‘syrinx’ for short) and syringobulbia? [2]
Syringomyelia (‘syrinx’ for short)
- describes a collection of cerebrospinal fluid within the spinal cord
Syringobulbia is a similar phenomenon in which there is a fluid-filled cavity within the medulla of the brainstem. This is often an extension of the syringomyelia but in rare cases can be an isolated finding.
What are the causes of syringomyelia? [4]
Chiari malformation: strong association
- a problem in which a part of the brain (the cerebellum) at the back of the skull bulges through a normal opening in the skull where it joins the spinal canal. T
trauma
tumours
idiopathic
Describe the classic presentation of syringomyelia [+]
Classical presentation of a syrinx is a patient who has a ‘cape-like’ (neck and arms) loss of sensation to temperature but preservation of light touch, proprioception and vibration.
- Classic examples are of patients who accidentally burn their hands without realising
- This is due to the crossing spinothalamic tracts in the anterior commissure of the spinal cord being the first tracts to be affected.
Other symptoms:
* spastic weakness (predominantly of the upper limbs)
* paraesthesia
* neuropathic pain
* upgoing plantars and bowel and bladder dysfunction
Prolonged syringomyelia:
Scoliosis will occur over a matter of years if the syrinx is not treated. It may cause a Horner’s syndrome due to compression of the sympathetic chain, but this is rare
Which spinal tract is classically affected first in syringomyelia [1]
crossing spinothalamic tracts in the anterior commissure of the spinal cord are the first tracts to be affected.
How do you Ix syringomyelia? [2]
Investigation requires a full spine MRI with contrast to exclude a tumour or tethered cord.
A brain MRI is also needed to exclude a Chiari malformation.
Tx of syringomyelia? [1]
Treatment will be directed at treating the cause of the syrinx.
In patients with a persistent or symptomatic syrinx, a shunt into the syrinx can be placed.
Clinical features of HD? [4]
Features typical develop after 35 years of age
* chorea
* personality changes (e.g. irritability, apathy, depression) and intellectual impairment
* dystonia
* saccadic eye movements
ZtF:
* Chorea (involuntary, random, irregular and abnormal body movements)
* Dystonia (abnormal muscle tone, leading to abnormal postures)
* Rigidity (increased resistance to the passive movement of a joint)
* Eye movement disorders
* Dysarthria (speech difficulties)
* Dysphagia (swallowing difficulties)
HD
Neuroimaging:
- While not diagnostic, neuroimaging can support the clinical findings. MRI or CT scans may show [] nucleus atrophy, but these changes are more evident in advanced stages of HD
Neuroimaging:
- While not diagnostic, neuroimaging can support the clinical findings. MRI or CT scans may show caudate nucleus atrophy, but these changes are more evident in advanced stages.
Describe the management for HD:
- Neurological management [3]
- Pyschiatric management [2]
- Nutrional [2] and dysphagia [3]
Neurological Management:
- Tetrabenazine is the first-line treatment for chorea in HD (works by depleting dopamine)
- Deutetrabenazine and valbenazine are alternatives if tetrabenazine is not tolerated.
- For patients with bradykinesia or rigidity, consider a trial of levodopa.
- Amantadine: May also help reduce chorea and has some mood-stabilizing effects.
- Drugs like olanzapine, risperidone, or quetiapine are sometimes used to manage chorea and psychiatric symptoms if associated
Psychiatric Management
* Selective serotonin reuptake inhibitors (SSRIs) or mirtazapine can be used to manage depression and irritability in HD patients.
* Cognitive behavioural therapy (CBT) should be considered for managing obsessive-compulsive disorder symptoms.
* Mood stabilisers like valproate or lamotrigine can be helpful for mood swings or irritability.
* Antipsychotics: These are also used to treat psychosis, severe agitation, or aggression.
Dysphagia Management
* A speech and language therapist should assess swallowing function regularly to minimise risk of aspiration pneumonia. Dietary modifications may be necessary.
* If oral feeding becomes unsafe despite interventions, percutaneous endoscopic gastrostomy (PEG) feeding should be considered.
Meige’s syndrome is made up with which two dystonia manifestations?
Blepharospasm +
oromandibular dystonia
Describe the medical [3] surgical [2] and other treatments [2] for dystonia
Medications:
* Anticholinergics: Drugs like trihexyphenidyl and benztropine help reduce muscle contractions by blocking the neurotransmitter acetylcholine.
* Benzodiazepines: Drugs like diazepam or clonazepam can help relax muscles and reduce spasms.
* Dopaminergic Agents: Levodopa or tetrabenazine may be used in certain forms of dystonia.
Surgical treatments:
- Deep Brain Stimulation (DBS): This is the most common surgical treatment for dystonia. Electrodes are implanted in specific brain areas, like the globus pallidus or subthalamic nucleus, to modulate abnormal brain signals. DBS is often used for generalized dystonia or severe focal dystonia unresponsive to other treatments.
* Selective Peripheral Denervation: Involves cutting nerves to specific muscles to reduce contractions. This is sometimes used for cervical
dystonia.
Other
* Physiotherapy/Occupational tx / exercise
* Botox injections - treat focal dystonia by temporarily paralyzing the overactive muscles. The effects last for 3-4 months, after which the injections may need to be repeated.
Describe why dystonias occur [1]
Its pathophysiology involves dysfunction within the basal ganglia, specifically in dopaminergic pathways
- This can result from various causes such as genetic mutations, brain injury or certain drugs.
Describe physiological tremor with regards to:
- Frequency
- Amplitude
- Distribution
- Posture
- Exacerbating Factos
- Frequency: between 8 to 12 Hz.
- Amplitude: low amplitude
- Distribution: hands and fingers
-
Posture: observed when maintaining a posture
(e.g., holding the hands outstretched) and is
considered an action tremor. -
Exacerbating Factors: emotional stress, fatigue,
caffeine or stimulants, thyroid dysfunction.
What frequency of tremor is essential tremor? [1]
Frequency of 6 to 8 Hz.
How long does essential tremor need to occur for before a dx? [1]
What would the tremor look like? [1]
- Tremor must be present for at least three years to be classified as ET
- Progressive bilateral action tremor in both arms, although theseverity may differ between sides.
What is the freq. of PD tremor? [1]
Typical frequency of a
Parkinson’s tremor is 4-6 Hz.
What is the Westphal variant of HD? [1]
rare juvenile-onset cases:
- parkinsonism, dystonia, myoclonus, epilepsy, chorea may be absent
Describe the different classifications of tics [2]
1. Motor
* Simple: eye blinking, facial grimacing, shoulder shrugging, and head jerking.
* Complex: involve sequences of coordinated movements.
* echopraxia (repeating someone else’s movements), palipraxia (repetition of one’s own movements)
2. Phonic
* Simple phonic: grunting, barking, moaning, throat clearing, sniffing, hollering…
* Complex: echolalia (repeating someone else’s words or phrases), palilalia (repeating one’s own
utterances, particularly the last syllable, word, or phrase), coprophenomena (RARE!)→shouting of
obscenities, profanities, or other insults
Describe the characteristics of tics [+]
- Urge/Relief (80% pts): premonitory feelings or sensations, which are relieved by the execution of the
tic. - Suppressibility
- Precipitating factors (attention to the tic, stress or relaxation)
- Decrease with distraction
- Wax and wane nature
- Fluctuate spontaneously
- Motor tics persist during sleep in the majority of patients
Describe what is needed for Tourette syndrome criteria [1]
Tourette syndrome criteria:
* Onset < 18 yo and chronic duration (>12 months).
* Both multiple motor tics and one or more phonic tics must be
present at some time during the illness, although not necessarily concurrently
Describe the tx of tics:
- Behavioural therapy [2]
1. Behavioral Therapy
Habit Reversal Training (HRT): Helps individuals recognize the urge to tic and replace the tic with a more
appropriate, competing response.
Relaxation Techniques: Stress and anxiety can exacerbate tics, so learning relaxation strategies like deep
breathing and progressive muscle relaxation can help manage tics
2. Medications:
* Alpha-2 Adrenergic Agonists: Such as clonidine. These are often used as a first-line medication,
especially in children, because they have fewer side effects. Particularly useful in tics with coexisting
ADHD.
* Antipsychotic Medications: Such as aripiprazole, risperidone, and haloperidol. These can be effective in reducing tics but may have side effects like weight gain and sedation.
* Dopamine Depleters: Such as tetrabenazine. These reduce the amount of dopamine in the brain, which can help control tics.
