Neurodegenerative diseases Flashcards
A 28 year old Norwegian woman presents to A&E after she was unable to feel the hot water on her left leg whilst taking a bath. CSF analysis demonstrated oligoclonal bands that were unmatched with the serum. Which of the following would most likely confirm a diagnosis of Multiple Sclerosis?
A Multiple lesions on MRI that all enhanced with gadolinium
B The patient’s symptoms reoccur 1 year later
C The patient develops blurry vision in one eye a year later
D The patient reports blurry vision currently
E A 1 year follow up finds oligoclonal bands matched with the serum
C The patient develops blurry vision in one eye a year later
Define multiple sclerosis
A chronic inflammatory multifocal, demyelinating disease of the central nervous system of unknown cause, resulting in loss of myelin and oligodendroglial and axonal pathology
What are the symptoms of multiple sclerosis
- Plaques on optic nerve - optic neuritis - vision loss and pain
- Charot’s neurological triad - dysarthria, nystagmus, intention tremour
- Plaques on sensory neurones - numbness, parasthesia, pins and needles
- Plaques in the ANS - bladder (urinary incontinence/urgency) sexual dysfunction
- plaques on motor neurones - weakness of the limbs with spasticity and hyper-reflexia
- Disturbances in higher order activities- poor concentration + critical thinking, depression + anxiety
- Lhermitte’s sign - electric shock radiating down patients neck triggered by neck flexion
What are the clinical signs of multiple sclerosis
- Fundoscopy - inflamed optic disc
- CN exam - internuclear ophthalmoplegia: for example when R eye glare to the left. R eye cannot look past the midline
- Lhermitte’s sign - electric shock radiating down patients neck triggered by neck flexion
- Charot’s neurological triad - dysarthria, nystagmus, intention tremour
What are the risk factors of multiple sclerosis
- Female
- Vitamin D deficiency (pts with Scandinavian origin)
- HLA DLR B1*15
- Other autoimmune conditions such as SLE
What can be found on a MRI of a patient with multiple sclerosis
White matter plaques
These are pathological substrate of relapses
What is the most common type of multiple sclerosis
Relapsing remitting (RR) MS
To make a clinical diagnosis of multiple sclerosis, what should be present
- absence of an alternative diagnosis
- Dissemination in time
- Dissemination in space
What stain is used in MRI to diagnose multiple sclerosis
Gadolinium contract (GAD)
How can GAD be used in the diagnosis of multiple sclerosis
- acute inflammation
- breakdown of BBB
- GAD penetrates CNS
- GAD enhances active lesions
(older lesions remain darker, so looking at older lesions in different parts of the brain can diagnose MS)
What can be said about the oligoclonal bands in multiple sclerosis
- Oligoclonal bands were present in the CSF but not the serum
Must only be in the CSF otherwise IgG could have been from an infection at the periphery.
CSF bands are 95% sensitive for MS, but not specific as could also be infection of the CNS
How can visual evoked potentials be used in the diagnosis of multiple sclerosis
These look for subtle abnormalities in the visual pathways (commonly affected in MS) which may help clinicians to pick up subclinical features even the patient was not aware of
A 40 year old woman visits her GP complaining of tiredness. On questioning, she reports getting tired when climbing the stairs or during a conversation. She often has to stop what she is doing to regain her energy. The GP asks her to look upwards, and after a few seconds she begins to develop ptosis. What is the most likely diagnosis?
A Iron Deficiency Anaemia
B Myasthenia Gravis
C Lambert Eaton Myasthenic Syndrome
D Carcinoma
E Horner’s Syndrome
B Myasthenia Gravis
What are the symptoms of myasthenia gravis
- Muscles fatigue with use (symptoms at the end of the day)
- Ptosis
- Diplopia
- Dysarthria
- Dysphagia
+/- SOB
What are the clinical signs of myasthenia gravis
- Fatigable muscles
2. Normal reflexes
What are the antibodies that can be produced in myasthenia gravis
- anti-AChR antibody
2. MuSK (Muscle-Specific Kinase) protein
What conditions is myasthenia gravis associated with
- Thymic hyperplasia (70%)
2. Thymoma (10%)
What investigations can be done to diagnose myasthenia gravis
- Bloods - anti-AChR and anti-MuSK
- EMG (can demonstrate muscle weakness, action potentials will gradually decreased)
- CT/MRI (CT chest can detect thymoma)
What are the symptoms of Lambert Eaton Myasthenic Syndrome
- Weakness where muscles improve with use (symptoms in the morning)
- Difficulty walking
- weakness in upper arm and shoulders
- similar symptoms to myasthenia gravis
- Autonomic symptoms include dry mouth, constipation and incontinence
What are the clinical signs of Lamber Eaton Myasthenic syndrome
- Muscle function better following use
2. hyporeflexia
What is Lambert Eaton Myasthenic Syndrome
The immune system attacks calcium channels on nerve endings
What conditions is Lambert Eaton Myasthenic syndrome associated with
- Small cell lung cancer
2. Autoimmune disease
What are the investigations to diagnose Lambert Eaton Myasthenic syndrome
- Bloods - anti-VGCC
- EMG
- CT/MRI (for cancer detection)
What are the symptoms of motor neurone disease
- progressive muscle weakness
- Dysphagia
- Shortness of breath
What neurones does motor neurone disease spare
- Occulomotor
- sensory function
- autonomic function
What are upper motor signs
- increased weakness
- increased reflexes
- No fasciculations
- increased tone
- Extensor response present
What are lower motor signs
- increased weakness
- atrophy - wasting of the tongue and thenar muscles in the hand and
- reduced reflexes
- fasciculations present
- Tone decreased
- Extensor response absent (babinski’s sign)
What condition has both upper and lower motor neurone signs
Motor Neurone Disease
Which muscles undergo wasting in motor neurone disease
- wasting of the thenar hand muscles (base of the thumb)
2. Wasting of the tongue muscle (bulbar onset)
What is the pathophysiology behind motor neurone disease
Normally proteins that need degradation are marked with ubiquitin.
This malfunctions in in MND
These proteins build up which eventually kill the motor neurones.
Upper and lower motor neurones killed.
This leads to death of the corticospinal tract
What genetic risk factor increases the chances of developing motor neurone disease
97% of MND patients have ubiquitin inclusions positive for TDP-43
Normally TDP-43 is found in the nucleus where it is involved with normal DNA and RNA function.
In MND, the TDP-43 protein is found in the cytoplasm where it is tagged with ubiquitin. However, it is not degraded and builds up and leads to cell death.
A 70 year man is referred to a neurologist by his GP. The referral letter notes that the man has slowly been struggling to get around and carry out basic activities like cooking dinner, finding he struggles to initiate movement. The letter also notes that the patient has a resting tremor and rigid upper arms. When the neurologist calls the patient into the room, what gait does he expect the patient to most likely have?
A Ataxic
B Hemiplegic
C Shuffling
D Scissor
E Choreiform
C Shuffling
What is the classical Parkinsonism triad
- Bradykinesia
- Rigidity
- Resting tremur
What are the 6Ms that help describe Parkinson’s symptoms
- Monotonous
- Micrographia (small handwriting)
- HypomiMesis (expressionless face)
- March a petit pas (gait with little steps)
- Misery (depression)
- Memory loss (dementia)
What are the symptoms of Parkinson’s disease
- Pill-rolling tremor (resting)
- Cog-wheeling rigidity
- Stooped posture
- expressionless face
- Bradykinesia, hypokinesia, akenesia (due to difficulty initialting movement)
- Late feature: postural instability which can lead to falls
- Depression
- Dementia
- Sleep disturbances
- difficulty smelling