Lecture day 2 Flashcards
What does ALS stand for?
Amyotrophic lateral sclerosis
What is the median survival for someone with ALS?
24-50 months
10% of patients will live for 10 years
What is the median age of onset for ALS?
51-66
What is the pathophysiology of ALS?
TDP-43 cytoplasmic aggregates
Normally resides in nucleus. In ALS, this will move to cytoplasm and aggregate
What is the most common genetic link in ALS?
C9ORF72
ALS lies on the spectrum with frontotemporal dementia
How does ALS affect UMN and LMN?
Classical ALS is a combination of UMN and LMN impairment
In upper motor neuron (corticospinal tract) → impairment
- Spasticity
- Hyper-reflexia
- Babinski reflex
- Weakness
Lower motion neuron (anterior horn cell)
- Atrophy
- Fasciculations
- Hypo-reflexia
- Weakness
What are clinical signs of ALS?
- Atrophy of thenar eminences and first dorsal web spaces
- Atrophy of the tongue
- Upper limb fasciculation
What is the disease heterogeneity in onset in ALS?
1/3 starts as bulbar
1/3 starts lower limb
1/3 starts with upper limb
What are typical presenting symptoms for ALS?
- Speech slurring or hypophonia
- Clumsiness of hands
- Foot drop
- Asymmetric at onset
- Absence of major sensory symptoms
What are associated features of ALS?
- Fasciculations
- Cramps
- Gait imbalance
- Falls
- Emotional lability
- Weight loss
What guidelines would you use to diagnose ALS?
El Escorial
How long does it often take to go to onset of symptoms to diagnosis of ALS?
12 months
What investigations can you do for ALS?
Needle electromyography: mixed pattern of acute and chronic denervation
Diagnosis remains clinical - imaging excludes mimics
What are features of acute denervations?
Fibrillations, positive sharp waves and fasciculations (more precisely a sign of neuronal hyperexcitability)
What are features of chronic denervations?
Large, long, polyphasic motor unit action potentials (indicating compensatory reinnervation)
What are differential diagnoses for ALS?
Very few conditions cause mixed UMN and LMN damage
Syphilis is the great imitator
Sometimes vit B12 deficiency
What diseases mimic LMN impairments?
Spinal degenerative disorder Multifocal motor neuropathy Myasthenia graves HIV Vitamin B12 deficiency
What diseases mimic UMN impairments?
Stroke MS Neurosyphilis hereditary spastic paraplegia Leukodystrophies Vitamin B12 deficiency
What are established treatment options?
Mainly riluzole
Some symptomatic treatments
What are the benefits of Riluzole?
Glutamate antagonist which improves survival by 20%
What are primary headaches?
Migraine
Tension-type headache
Trigeminial autonomic cephalalgias
What are secondary headaches?
- Trauma or injury to the head
- Cranial or cervical vascular
- Intracranial non-vascular
- Substances
- Infection
- Homeostasis
What are the characteristics of a migraine?
Typically lasts 4-72 hours
Unilateral, pulsating, moderate to severe, aggravated by daily activity
Nausea/vomiting or photophobia and phonophobia
What are the characteristics of a cluster headache?
5-180 minutes
Severe or very severe unilateral orbital or temporal
Often with infection, eyelid oedema, nasal congestion, forehead fo facial sweating, mitosis or ptosis
Between 8 per day to one every other day
What are red flags for headaches?
- Systemic symptoms (fever or weight loss)
- Altered consciousness
- Age over 50 (unusual to have sudden onset headaches - more likely to be secondary)
- Postural or positional (CSF venus fistulla)
- Precipitated: Valsalva, exertion, sex
- Papilloedema
What are the differentials for a thunderclap headache?
- Subarachnoid haemorrhage
- Intracerebral haemorrhage
- Cerebral venous thrombosis
- Arterial dissection
- Reversible cerebral vasoconstriction syndrome
- Pituitary apoplexy
What are the characteristics of a raised ICP headache?
- Worse in morning
- Better in upright
- Worse with Valsalva
What are the characteristics of a lower ICP headache?
Worse as day goes on
Better recumbent
What are the characteristics of idiopathic intracranial hypertension?
Persistent, dull, pressing bilateral headache. Aggravated by coughing, pressing and physical activity. Potential nausea
Visual disturbances: decrease in acuity, increase in blind spot, papilloedema
How would you treat migraine?
- NSAIDs
- Triptans (use when patient is not pain free after 2 hours on NSAIDs)
- Antiemetics (occasionally, but not often)
- Metoclopramide
- Domperidone
Preventive treatment (use when around 7 migraines per month)
What preventative treatment could you give for migraines?
Metoprolole
Valproate
Flunarizine
What is a medication overuse headache?
- Headache occurring on ≥ 15 days/month in a patient with a pre-existing headache disorder
- Regular overuse for > 3 months of one or more drugs that can be taken for the acute and/or symptomatic treatment of headache
How would you manage a cluster headache?
- 100% oxygen (12-15 l/min) (after 10 minutes the headache is gone)
- Triptans (sc or nasal)
When would you give preventative treatment in a cluster headache?
ALWAYS
What are the preventative treatments for cluster headaches?
- Verapamil (works most of the time)
2. Topiramate, lithium
What are possible causes of tingling limbs?
- Stroke or TIA
- Spinal cord pathology
- Spinal nerve compression
- Peripheral nerve compression
- Nerve damage due to trauma
- MS
- Endocrine
- Vitamin deficiency
- Nerve toxicity
What can cause spinal cord compression?
metastatic malignancy, herniated disc
What can cause peripheral cord compression?
Tumour, enlarged blood vessels, infection
What endocrine disturbances can cause tingling limbs?
Diabetes
Hypothyroidism
What vitamin deficiencies can cause tingling limbs?
Vitamin B12
Thiamine
What substances can cause nerve toxicity?
Alcohol
Lead
What is hyperpathia?
Heightened noxious sensation
What is allodynia?
Noxious response to non-noxious stimuli
What is the MRC scale?
Muscle Power Scale
What are the grades of the MRC scale?
Grade 0 - no muscle movement
- Grade 1 = flicker or trace of muscle movement
- Grade 2 - active movement with gravity
- Grade 3- active movement against gravity
- Grade 4 = active movement against gravity and resistance
- Grade 5 = normal power
What kind of lesions would result in muscle atrophy?
UMN
What kind of lesions would result in muscle wasting?
LMN
What kind of lesions would result in Babiski sign?
UMN
What kind of lesions would result in hyperreflexia?
UMN
What kind of lesions would result in hyporeflexia?
LMN
What kind of lesions would result in a foot drop?
LMN
What kind of lesions would result in fasciculations?
LMN
What muscle, nerve and root are responsible for shoulder abduction?
Deltoid
Axillary
C5
What muscle, nerve and root are responsible for elbow flexion?
Biceps
Musculocutaneous
C5, C6
Brachioradialus
Radial
C6
What muscle, nerve and root are responsible for elbow extension?
Triceps
Radial
C7
What muscle, nerve and root are responsible for radial wrist extension?
Extensor carpi radialis longus
Radial
C6
What muscle, nerve and root are responsible for finger extension?
Extensor digitorum communis
Posterior interosseeous nerve
C7
What muscle, nerve and root are responsible for finger flexion?
Flexor pollicis longus
Anterior interosseous
C8
Median nerve C8
Flexor digitorum profundus
Ulnar (ring and little finger)
What muscle, nerve and root are responsible for finger abduction?
First dorsal interosseous and abductur digiti minimi
Ulnar
T1
Abductor pollicis brevis
Median
T1
What muscle, nerve and root are responsible for hip flexion?
Iliopsoas
L1 L2
What muscle, nerve and root are responsible for hip adduction?
Adductors of the hip
Obturator
L2, L3
What muscle, nerve and root are responsible for hip extension?
Gluteus maximus
Sciatic
L5, S3
What muscle, nerve and root are responsible for knee flexion?
Hamstring
Sciatic
S1
What muscle, nerve and root are responsible for knee extension?
Quadriceps
Femoral
L3, L4
What muscle, nerve and root are responsible for ankle dorsiflexion?
Tibialis anterior
Deep peroneal
L4
What muscle, nerve and root are responsible for ankle eversion?
Peronei
Superficial peroneal
L5, S1
What muscle, nerve and root are responsible for ankle plantar flexion?
Gastrocnemius, soleus
Tibial
S1, S2
What muscle, nerve and root are responsible for big toe extension?
Extensor hallucis longus
Deep peroneal
L5
What investigations would you do for tingling limbs?
- Blood tests
- HIV test
- Environmental exposure
- Nerve conduction studies
- EMG
What is the function and velocity of type alpha fibres?
Proprioception, somatic motor
70-120 m/s
What is the function and velocity of type beta fibres?
Touch and pressure
30-70 m/s
What is the function and velocity of type gamma fibres?
Motor to spindle muscles
15-30 m/s
What is the function and velocity of type delta fibres?
Pain, cold, touch
12-30 m/s
What is the function and velocity of type B fibres?
Preganglionic automatic
3-15 m/s