Going off legs

Question 1

UMN - features

Answer 1

• increased tone
• normal till disuse atrophy, some muscle weakness
• absence of fasciculations
• brisk reflexes (hyper-reflexia)
• +ve plantar/babinski = thumb upgoing

Question 2

LMN - features

Answer 2

• hypotonia
• prominent muscle weakness and atrophy
• fasciculations
• decreased or absent reflexes (hyporeflexia)
• -ve plantar/babinski = thumb downgoing

Question 3

UMN - DDx

Answer 3

• bilateral UMN (3 M’s) = MS, MND (no sensory loss), myelopathy (cervival myelopathy, disc prolapse, trauma, transverse myelitis, syringomyelia etc)
• unilateral UMN = stroke, MS, haemorrhage, trauma, abscess, AVM

Question 4

LMN - DDx

Answer 4

• bilateral LMN = with abnormal sensation –> vasculitis (SLE, RA), infection (herpes zoster, HIV, syphilis), DM, charcot marie tooth, B12 deficiency (folate def anemia)
  normal sensation –> GBS, CIDP, myotonic dystrophy
• unilateral LMN = radiculopathy (disc herniation, spinal stenosis, cervical spondylosis), plexopathy (brachial neuritis, erb’s palsy), nerve palsy (CTS, ulnar/radial/ axillary/common peroneal nerve palsy)
• MS, MND

Question 5

Gait apraxia

Answer 5

Apraxia = loss of ability to execute previously
learned skills and gestures. Results from loss of cortical integration pathways

Gait Apraxia = damage to frontopontocerebellar tract

• Difficulty starting movements. Shuffling - slow, wide based, small hesitant steps / frequent stops.
• Intact muscle power and tone, coordination, sensation, extrapyramidal function, intellect, motivation, attention
• Poor truncal mobility
• Falls due to minor balance disturbances
• magnetic gait, inability to raise foot off of the floor

Question 6

Gait apraxia - DDx

Answer 6

- most common = stroke
Other
– Normal pressure hydrocephalus (NPH)
– Neurodegenerative disorders – esp. dementias
– Various frontal lobe lesions

Question 7

Gait ataxia

Answer 7

• Gait – wide based and unsteady, unable to walk heel-toe, often stagger and resemble persons who have ingested excessive alcohol
Ataxia – other features = Intention tremor, past pointing, Dysmetria, Dysdiadochokinesis, Nystagmus, Dysarthria

Question 8

Ataxic gait - DDx

Answer 8

• degenerative
• Toxic – alcohol and drugs
• Deficiencies – thiamine, Vit E
• Vascular
• Metabolic/endocrine - thyroid
• Autoimmune eg MS, paraneoplastic
• Genetic eg Friedreich’s, spinocerebellar ataxias (SCA)
• Infectious – acute cerebellitis

Question 9

Guillian Barre Syndrome - definition

Answer 9

Acute inflammatory polyneuropathy characterised by motor difficulty, absence of deep tendon reflexes, paraesthesias without objective sensory loss, and increased CSF albumin
Immune-mediated attack on myelin sheath or Schwann cells of sensory and motor nerves, frequently triggered by an antecedent infection within the 6 weeks before symptom onset, most commonly URTI or gastroenteritis (Campylobacter jejuni*, CMV, EBV, Mycoplasma pneumoniae etc)

*classically Campylobacter jejuni

Question 10

GBS - clinical features

Answer 10

• Progressive symmetrical muscle weakness usually affecting lower extremities before upper extremities and proximal muscles before distal muscles accompanied by paraesthesias in the feet and hands.
  respiratory distress (dyspnoea on exertion and SOB)
  speech problems, dysarthria, dysphagia
  back/leg pain
  areflexia/hyporeflexia
  facial weakness, facial droop
  diplopia

Question 11

GBS - investigations

Answer 11

lumbar puncture (LP) (raised CSF protein with a normal white blood cell count)
nerve conduction studies (reduced motor nerve conduction velocities and patchy demyelination)
LFTs (raised AST and ALT)
antiganglioside antibody

Question 12

GBS - treatment

Answer 12

• plasma exchange
• intravenous immunoglobulin (IVIG)
• supportive treatment = monitor pulse and BP, DVT prophylaxis for non-ambulatory pts, rehabilitation, physio, OT, speech therapy etc

Question 13

Signs of cord lesion vs peripheral neuropathy

Answer 13

CORD (eg brown sequard, MS)
Spasticity • UMN weakness pattern • Brisk reflexes
(unless acute lesion) • Extensor plantars • Sensory level

NEUROPATHY (eg GBS)
• Tone normal • LMN weakness pattern •Reduced/ absent reflexes • Flexor plantars • Sensory signs> distally

In a cord lesion, notice the specific level of sensory loss eg below T10, while in polyneuropathy it starts distally and improves proximally

Question 14

Subacute combined degeneration of spinal cord

Answer 14

Degeneration of the posterior and lateral columns of the spinal cord as a result of vitamin B12 deficiency (most common), vitamin E and copper deficiency

• weakness of legs, arms, trunk, tingling and numbness that progressively worsens.
• Bilateral spastic paresis may develop and pressure, vibration and touch sense are diminished.
• ataxic gait and positive romberg’s, falls
• absent ankle and knee jerks with upgoing plantars

Question 15

Gait problems - types

Answer 15

1. Ataxic gait - wide base (cerebellar)
2. Gait apraxia - e.g. stroke
3. Antalgic Gait - non-weight bearing, e.g. OA
4. Shuffling Gait - parkinsonian

Question 16

Romberg’s Test

Answer 16

A person requires at least two of the three following senses to maintain balance while standing: proprioception (the ability to know one’s body position in space); vestibular function (the ability to know one’s head position in space); and vision.

Sensorimotor integration is carried out by the cerebellum and by the dorsal column.

Romberg’s test is positive in conditions causing sensory ataxia such as:

• Vitamin deficiencies such as Vitamin B12
• Conditions affecting the dorsal columns of the spinal cord, such as tabes dorsalis (neurosyphilis)
• Sensory peripheral neuropathies), such as chronic inflammatory demyelinating polyradiculoneuropathy
• Friedreich’s ataxia
• Ménière’s disease