What are the presenting complaints in HYPOkalemic periodic paralysis?
What is the inheritance and where is the mutation?
How do you treat?
- Episodic weakness without myotonia
- Lasts for hours to days!
- Often bought on by exercise, awakening from sleep, cold temperatures or eating high carb/sodium meals.
- Autosomal dominant - SCN4A or CACNA1S
- Carbonic anhydrase inhibitors or potassium sparing diuretics
What are the presenting complaints in HYPERkalemic periodic paralysis?
What is the inheritance and where is the mutation?
How do you treat?
- Episodic weakness without myotonia
- Lasts for minutes to hours
- Bought on by fasting or exercise
- AD - SCN4A
- Thiazide diuretics
Which periodic paralysis affect asian men and how do you treat?
- Thyrotoxic periodic paralysis
- Treat with propranolol
- KCNJ18 mutation
PMP22 deletion causes?
And PMP 22 duplication causes?
Where and what is the histological abnormality in HSMN 1A? What NCS/EMG changes does this cause?
- This is a demyelinating neuropathy.
- Causes onion-bulbing of Schwann cells due to repeated episodes of remyelination.
- Causes decrease conduction velocity with no conduction block.
What is the inheritance patterns and neuropathy type of the HMSNs?
- Type 1 - AD - Demyelinating
- Type 2 - AR - Axonal
- Type 3 - AR - Demyelinating
Medications that worsen MG?
- All the anti-arrhythmics
What is the most sensitive diagnostic test for MG?
What does it show?
- Single fibre EMG
- Shows jitter and blocking
What are the signs of neonatal myasthenia, what causes them and how do you manage?
- Weakness, resp failure, arthrogryposis
- Will resolve in a month
What is the main histopathological finding in steroid myopathy?
Typer 2 fibre atrophy
The EMG in a patient with myopathy is likely to show?
Early motor unit recruitment
Presentation of IBM?
- Over the age of 50.
- Proximal wasting in the lower limbs and distal in the upper.
- Often has bulbar involvement
- Elevated CK
Presentation of Dermatomyositis?
- Associated rash on face/trunk/knuckles (gottron's)
- Increased risk of malignancy
Which Antibody is associated with it?
What is the pathological finding on muscle biopsy?
- Perifasicular atrophy
What is the pathological finding?
Rimmed vacuoles best seen with trichrome stain.
Anti GM1 antibodies are associated with...
- Campylobacter jejuni infections
What does Dapsone cause?
Motor axonal neuropathy
What does diptheria do?
- Causes a demyelinating polyneuropathy similar to GBS
- AND a pseudomembranous pharyngitis
How does tetanus cause opisthotonus?
Block the release of glycine and GABA
What is the typical presentation of spinobulbar muscular atrophy?
- Kennedy's disease
- Typically bulbar symptoms early, then widespread wasting and weakness.
- Prominent perioral fasiculations
Spinobulbar muscular atrophy gene and what is the abnormality?
- Androgen receptor gene
- X linked recessive
- Trinucleotide repeat disorder - CAG
A well man presents with severe right shoulder pain followed several days later by right arm weakness? What provokes this condition? What is the heredity of the genetic form?
- Idiopathic brachial neuritis
- Gets better with time
- Commonly provoked by excessive exercise, childbirth, infection, vaccination, surgery and IVDU.
- The hereditary form is Autosomal dominant
- Can also affect the lumbosacral plexus?
What is the histopathological finding in HNPP?
- Tomaculi! Sausage like areas of thickening!
- PMP 22 deletion
FSHD and OPMD inheritance patterns?
Both autosomal dominant
What are the pathological findings in ALS?
- Atrophy in the spinal cord and motor strip.
- Loss of pyramidal betz cells in the cortex and alpha motor neurons in the anterior horn.
- Bunina bodies are found in the cell bodies of the LMN.
- Muscle pathology shows muscle fibre type grouping.
- EMG shows widespread denervation
How does riluzole work?
Inhibits glutamate release.
What is the gene affected in Myotonic dystrophy? What is the inheritance?
- DMPK gene - CTG trinucleotide repeat with anticipation
- Autosomal dominant
What lab test confirms Pompe's?
What is the other name for it and what accumulates in the body?
What pathology stain is used to detect this abnormal accumulation?
- Dried spot test
- Glycogen filled lysosomes - they stain with PAS (periodic acid-schiff)
What is the presentation of adult onset pompe's?
What are the EMG findings?
- Onset in 2nd-4th decade
- Weakness of trunk, proximal muscles and diaphragm.
- Electrical myotonia without clinical myotonia
What is a Martin-Gruber anastamosis?
Anatomical variant in which the median nerve innervates muscles in the ulnar nerve distribution.
What does the Lateral cord of the brachial plexus do?
Elbow and wrist flexion and lateral forearm sensation
What does the posterior cord of the brachial plexus do?
- Elbow, wrist and finger extension and shoulder abduction
- Sensation to posterior hand and arm.
What does the medial cord do?
- Thumb and finger flexors, intrinsic hand muscles
- Medial forearm sensation.
What can make MMN worse?
What is the presentation of MMN?
Slowly progressive, asymmetric, multifocal weakness without very much wasting.
What is Kennedy's disease?
- A type of Spinal muscular atrophy.
- X-linked disorder that presents with Bulbar weakness, prominent perioral fasiculations and androgen sensitivity (gynaecomastia, testicular atrophy, azoospermia)
- CAG repeat - polyglutamine
What is Brown-Vialetto-van Laere sydrome
- A type of SMA
- Onset in adolescence
- Progressive bulbar palsy with Bilateral sensorineural hearing loss
- tongue atrophy, fasiculations and dysphagia
What is Hirayama's disease?
- Juvenile monomelic amyotrophy
- Predominantly affects C7-T1 nerve roots
Spinal muscular atrophy - Key presenting features?
Weakness, wasting and fasiculations.
SMA underlying gene mutation? Whats its role
SMN gene involved in mRNA splicing
When do the SMAs present and with what characteristics?
- SMA 1 and 2 present in childhood
- SMA 3 - adulthood - usually with a CK 10x normal - also known as wohlfart-kugelberg-welander
What are the characteristics of FSHD? How does it differ from the other muscular dystrophies?
- Descending, asymmetrical weakness involving face, scapula, upper arm, lower leg and hip girdle.
- Differs from the others due to prominent PAIN
What conditions are associated with FSHD?
- Retinal vasculopathy
- Sensorineural hearing loss
Characteristics of Oculopharyngeal muscular dystrophy?
- More common in French Canadians and Bukhara Jews
- Autosomal dominant condition
- Presents in 5th/6th decade of life with progressive ptosis and dysphagia
- Classic muscle biopsy finding of Intranuclear tubular filaments
How do you differentiate cauda equina from conus syndrome?
- Conus is symmetrical with mixed signs and early sphincter involvement
- Cauda is asymmetric with LMN signs only and late sphincter involvement
Foot drop with preserved ankle inversion?
Its the common peroneal!!
What is meralgia paraesthetica? What causes it?
- Severe painful paraesthesia over the lateral thigh
- Caused by compression of the lateral femoral cutaneous nerve (innervated by L2/3)
- Caused by obesity, pregnancy, tight belts, tumors, prolonged sitting, diabetes and excessive wt loss.
What is associated with critical illness myopathy?
What is the histological abnormaility?
- Associated with Steroid and NM blocking drug usage
- Selective loss of myosin from myofibrils
- "Myosin losing myopathy"
What is the EMG pattern in Myotonic dystrophy?
- Myotonic discharges with waxing and waning amplitude
- The dive bomber pattern
A patient with cold and exercise induced muscle stiffness with intermittent paralysis?
- Paramyotonia congenita.
- Its 'para' because it gets worse with exercise rather than better
- Caused by a mutation in SCN4A gene
Which condition has no clinical myotonia but does have electrical myotonia?
Pompe's - acid maltase deficiency
What is McArdles disease?
- Myophosphorylase deficiency.
- Exercise intolerance from childhood including myalgia, cramps, normal exam, normal lactate
- Raised CK and Myoglobinuria
Whats is the most sens and specific way to detect carpal tunnel?
median sensory nerve conduction
What is the most common mitochondrial myopathy?
- Progressive external opthalmoplegia
- Pigmentary retinopathy
- Cerebellar ataxia
- High CSF protein
- Leukoencephalopathy and basal ganglia calcification
Rough differences in the CMTs?
- CMT1 = Autosomal dominant and demyelinating
- CMT2 = Autosomal dominant and axonal
- CMT3 = AD Childhood onset with delayed motor milestones and severe demyelination
- CMT4 = Autosomal recessive
What carries a worse prognosis for MND?
- A definite diagnosis of MND based on revised El Escorial criteria
- Bulbar onset,
- Presentation after 80 years of age and
- Lower FVC at diagnosis
Family history of MND does not affect prognosis.
What carries a better prognosis for MND
- Longer delay from onset to diagnosis,
- Onset before the age of 40 years and
- Spinal onset of disease carry a better prognosis.
Primary lateral sclerosis?
- Progressive upper motor neurone disorder,
- Often beginning in the 5-6th decade of life,
- Accounts for 1-4% of MND.
- More benign prognosis than ALS.
- Symptoms usually start in the legs. Patients report stiffness, poor balance and falls.
- Bulbar symptoms can such as dysarthria and dysphagia eventually develop.
- Urinary dysfunction is sometimes reported.
What differentiates PLS from ALS?
- Fasciculations and muscle atrophy are absent.
- More benign prognosis
- ALL UMN with stiff gait
In MND - what is a better marker of resp insufficiency than FVC?
The sniff nasal pressure test
Whats the recovery rate of Parsonage-Turner?
Only 10% make full recovery at 3 years
Sub-acute autonomic failure?
- Autoimmune Autonomic failure.
- Half of cases are assoc with gnACHr (ganglionic nicotinic)
- Paraneoplastic forms are also seen in assoc with SCLC and Anti-Hu
How does obturator neuropathy present?
- Decreased inner thigh sensation
- Weakness of hip adduction and rotation.
Antibody associated with MMN?
Antibody associated with PCB variant of GBS?
Other name for Stiff person syndrome?
Progressive encephalomyelitis with Rigidity and Myoclonus
If Anti-AchR antibodies are negative, whats the chance of a thymoma?
<1%, Absence of ACHr antibodies has an NPV of <1%
What is Bing-Neel Syndrome?
The presence of lymphoplasmacytoid cells with anaemia, IgM kappa monoclonal gammopathy, and peripheral neuropathy suggests a diagnosis of Waldenström’s macroglobulinaemia (WM). CNS involvement by malignant cells is a rare complication of WM referred to as Bing-Neel syndrome (BNS) which usually manifests a few years after the diagnosis of WM.
Patient with a thymomectomy has worsening despite all the therapy? What do you do?
Repeat the CT chest - thymomas recur
Which feature occurs in Para-neoplastic LEMS but not in normal LEMS?
Which chemotherapy agents cause Sensory ganglionopathy?
Which vitamin in excess can cause sensory ganglionopathy?
- Vitamin B6 - pyridoxine
- often used in body building diets
- Most common mutation found in adult onset
- Autosomal dominant Hereditary spastic paraplegia – accounts for 40%
- 20% of patients have cognitive impairment
Sensorimotor symptoms in the lower limbs with Meningeal enhancement in a patient with advanced HIV?
Risk factors for Crit.illnerss neuropathy/myopathy?
- Greater severity of multiorgan dysfunction,
- Female sex
- Prolonged mechanical ventilation (not prolonged time of illness before ventilation)
What is the presenting feature of MNGIE?
What is the mutation that leads to it?
- Intestinal pseudo-obstruction.
- Also causes peripheral neuropathy, ptosis and opthalmoparesis.
- Caused by a mutation in the Thymidine phophorylase gene which is an autosomal gene but causes problems mostly in mtDNA.
- Can be thought of as a mitochondrial disorder in its presentation but is autosomal at a molecular level.
What is the gene abnormality in FSHD?
- 95% of FSHD patients have Abberant expression of DUX4 – the fewer D4Z4 repeats you have, the more expression occurs.
- 5% have no problem with D4Z4 but instead have a mutation in SMCHD1 which allows the DUX4 gene to be read more easily
When do you choose RIG over PEG?
When FVC is significantly reduced
What is the most common SMA?
SMA type 1
Whats the new kid on the block for SMN1 gene mutations?
- Onasemnogene abeparvovec
- one-off IV dose of AAV-9 delivered SMN1 gene replacement therapy.