Introduction to neurology and neurosurgery

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Introduction to neurology and neurosurgery

• References
• Lindsay K, Bone I (2004) Neurology and
  Neurosurgery Illustrated. 4/e. Churchill
  Livingstone, Edinburgh.
• Lundy Ekman L (1998) Neuroscience Fundamentals
  for Rehabilitation. WB Saunders, Philadelphia

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objectives

• Revise material from Neuroscience and
• Extend knowledge in preparation for third year
  clinical placements
• Students will gain an appreciation of terms,
  procedures and conditions they will encounter on
  a daily basis in the acute and rehabilitation
  placements

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content

• Examination (revision only)
• Investigations
• Neurosurgical procedures
• Common pathologies
• Intracranial
• Spinal cord
• Peripheral nervous system
• Muscles
• Multifocal

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neurological examination

• A general neuro exam involves
• History
• Conscious level
• Higher cerebral function
• Cranial nerve exam
• Upper limb function
• Trunk
• Lower limb function
• Posture and gait
• Physios do some or most of these and certainly
  need to be aware of the significance of all
  findings reported.

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investigations

• Skull xray
• CT scan
• MRI
• US
• Angiography
• Radionuclide imaging
• EEG

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investigations contin

• ICP monitoring
• Evoked potentials
• Visual, auditory, somatosensory etc
• Lumbar puncture
• CSF
• EMG
• Neuro-otological studies

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Neurosurgical procedures
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purposes for neurosurgery include

• Diagnosis - eg biopsy, lumbar puncture
• Evacuation eg haemorrhage, pus
• Excision eg mass lesion, eliptogenic focus
• Decompression eg tumour, abscess
• Relief of ? ICP eg bilateral frontal
  craniectomy
• Repair eg aneurysm, artery, dural tear, elevation
  of depressed skull fracture
• Drainage of CSF shunt, lumbar puncture

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• Other purposes (not covered in this lecture)
• Implant eg nerve stimulators, radioactive seeds
  (tumour treatment from within - brachytherapy)
• Transplant eg human foetal tissue (PD), stem
  cells
• Spinal surgery (eg following trauma, tumours etc)

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neurosurgery approaches

• Stereotaxy placement of burr hole / bone flap
  and safest approach for destruction of deep brain
  tissue located by using 3-D coordinates (CT /
  MRI)
• Burr hole hole drilled into the cranium
• Craniotomy opening into skull (via hole or
  flap)
• Craniectomy excision of part of the skull (bone
  is left out)
• Cranioplasty plastic surgery of the skull eg
  bone or plate replacement

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Stereotactic surgery Lindsay and Bone p 380
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Example of stereotactic system with CT/MRI
guidance eg for biopsy Lindsay and Bone p 380
13
Example of biopsy procedure Lindsay and Bone p
314

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Example of operative approaches Lindsay and Bone
p 309
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Craniotomy to remove EDH Lindsay and Bone p 228
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Example of evacuation of SDH Lindsay and Bone p
235
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neurosurgery techniques

• Lumbar puncture insert lumbar puncture needle
  to collect CSF usually at the L3/4 space (below
  L1 where spinal cord ends) contraindicated if
  ICP is increased since it may cause tentorial
  herniation (pressure gradient)

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Example of lumbar puncture Lindsay Bone p 55
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SAH - Aneurysm repairLindsay and Bone p 277

• Clipping dissection of arachnoid tissue around
  neck of aneurysm allows a clip to be positioned
  to prevent further rupture
• Wrapping muslin gauze or fascia lata is wrapped
  around fundus (rebleeding may occur)
• Trapping clip proximal and distal vessels ?
  bypass anastomosis (? risk of infarction)
• Common carotid ligation (collateral circulation
  through circle of Willis ? reverse flow from
  external carotid may prevent ischemia)

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aneurysm repair

• Balloon embolisation balloon inserted via an
  angiographic catheter is inflated in aneurysm sac
  - not optimal (risk rupture of aneurysm, embolic
  CVA, rebleed)
• Helical platinum coil embolisation tracker
  catheter guided through aneurysm neck introduces
  a coil on a delivery wire / electrical current
  releases coil from delivery wire

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Example of wrapping technique for aneurysm (L)
and pre/post images post coil embolisation (R)
Lindsay Bone p 285/6
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other techniques

• Surgical resection (remove parts of the brain
  for epilepsy, tumour etc)
• Drainage of abscess, CSF shunt

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Operative techniques for epilepsy Lindsay Bone
p 101
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Examples of abscess drainage procedures Lindsay
and Bone p 354
25
Examples of shunt techniques Lindsay and Bone p
373
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considerations post-neurosurgery

• Read surgery reports. Medical orders must be
  checked and followed eg
• Head position - may be flat and possibly
  positioned with drainage hole down (eg following
  SDH drainage) or 30 degrees up (eg where there is
  ? ICP or vasospasm following aneurysm repair)
• Rest in bed versus allowed to SOOB or mobilise
  (and if so, what distances eg to and from toilet)
• Monitored fluid intake / output eg nil by mouth
  / intake related to maintaining cerebral
  perfusion pressure and cerebral blood flow
• Restraint eg with irritable patient

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considerations post-surgery

• Monitoring and advising medical staff re
  complications
• DVT (both lower and upper limb)
• Cardiorespiratory eg aspiration, secretion
  retention
• Neurological deterioration eg ? weakness
• Musculoskeletal issues eg shoulder pain,
  contractures
• Neuropraxia, pressure areas (eg from compression
  while on operating table)
• Bone flap / helmet to be worn if flap left out

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Common neurological pathologies
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Intracranial conditions

• Acquired head/brain injury
• Refer to neuroscience clinical lecture
• Cerebrovascular disease
• Occlusion, rupture, disease of vessel walls,
  blood disturbance
• Lead to either ischemia/infarction (85) or
  haemorrhage (15)
• Refer to handout on arterial territories and
  syndromes for intra-cerebral haemorrhage

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Intracranial conditions

• Sub-arachnoid haemorrhage
• Between arachnoid tissue and brain tissue usually
  as a result of aneurysm. Headache, meningeal
  irritation, focal damage, LOC, etc.
• Aneurysms (intracranial)
• Usually saccular at BV bifurcations. Symptomatic
  only if rupture clinical picture related to
  site of haemorrhage. Surgical procedures to clip,
  ligate, wrap or trap, embolise etc.
• Arteriovenous malformations (AVM)
• Developmental anomalies of IC BVs tangled mess
  of blood vessels may lead to haemorrhage. Seen
  on angiography, CT or MRI. May be excised prior
  to rupture weighted decision.

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Intracranial contin

• IC tumours
• Commonest are gliomas, metastases and menigiomas
• Benign or malignant both space occupying
  lesions
• Classification according to cell type and may be
  graded according to malignancy eg IV is most
  malignant.
• Signs and symptoms dependent on site and rate of
  growth
• Rx radiotherapy, chemotherapy, neurosurgery for
  removal or debulking

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Intracranial contin

• IC abscess
• Infective collection extradural, subdural or
  cerebral. Less frequent due to use of
  antibiotics. Clinical presentation depends on
  site and infective agent. May require surgical
  procedure to drain/remove.
• Parkinsons Disease, chorea, other dystonias
• See neuroscience clinical lecture
• Hydrocephalus
• Increase in CSF volume usually due to impaired
  absorption (blockage). Can be acquired or
  congenital. Surgical Mx removal of blockage
  and/or shunt.

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• Chiari Malformation
• Herniation of cerebellar tonsils through foramen
  magnum. Type I, II and III indicate increasing
  herniation and increasing signs (III usually
  fatal by adulthood) eg ataxia, respiratory
  difficulties, spastic quadraparesis
  (syringomyelia). Mx surgical, symptoms.
• Friedrichs ataxia
• Inherited condition degeneration of cerebellum
  and SC, peripheral nerves. Mx PT etc

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Spinal cord and roots

• Spinal cord injury (traumatic sci)
• see neuroscience clinical lecture notes
• Disc prolapse, stenosis, spondylosis
• see MSP notes
• Spinal dysraphism defects of closure of neural
  arches (eg spina bifida)
• see neuroscience clinical lectures

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Spinal contin

• Syringomyelia
• Acquired Cavity or syrinx within central spinal
  cord may extend upwards to involve brainstem
  (syringobulbia) or downwards to filum terminale
• Cause pressure changes through epidural veins to
  spinal canal eg with straining / coughing with
  obstruction (eg from Chiari malformation, trauma,
  arachnoiditis) forces CSF into cord
• Dissociated sensory loss pain and temp
  wasting/weakness small muscles of hand, winging
  scapulae, long tract signs ? brainstem signs,
  hydrocephalus

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Peripheral nerves and muscles

• Neuropathies classified as
• acute, sub-acute or chronic
• motor, sensory or autonomic disturbance
• pathology affects axon and/or myelin
• causation and distribution.
• Guillain Barré
• see N/S lecture segmental demyelination,
  polyneuropathy, acute, motor and sensory, post
  viral, symmetrical, distal gtproximal

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Mononeuropathy

• Class 1 Demyelination (neuropraxia)
• focal compression / entrapment (eg carpal tunnel
  syndrome, associated with plaster casts that
  interfere with blood supply / cause local
  demyelination) recovery good
• Class 2 Axonal damage (axonotmesis)
• crush injury of nerve (CT and myelin sheath
  intact but axon disrupted with Wallerian
  degeneration) recovery good but slow
• Class 3 Axon and myelin degeneration
  (neurotmesis)
• nerve severed (disruption of CT, myelin sheath
  and axon) recovery slow, often with poor
  outcome

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Mononeuropathy

• Bells palsy
• cause - ? viral eg herpes simplex
• inflammation and swelling of the 7th CN in the
  facial canal (usually unilateral)
• pain over ipsilateral mastoid, weakness, impaired
  taste, hearing, salivation and lacrimation
• poor eye closure (may require tarsorrhaphy)

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• Plexus syndromes and other mononeuropathies
• Related to trauma of specific nerve/s see MSP
• Diabetic (poly)neuropathy
• Peripheral n damage related to poor diabetic
  control, damage either from metabolic disturbance
  or occlusion of nutrient blood vessels to n.
  Usually distal weakness, sensory loss
  autonomic. Mx control diabetes and symptomatic
• Charcot-Marie-Tooth (hereditary)
• Distal wasting in lower limbs due to genetic
  demyelination/axonal loss. Mx symptomatic.

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Muscle disorders

• Myasthenia Gravis
• disorder of neuromuscular transmission (reduced
  AcH receptors due to autoimmune disorder)
  weakness and rapid fatigue (see N/S notes)
• Duchenne Muscular Dystrophy (see Paeds notes)
• Other dystrophies with specific distribution
• Fascioscapulohumeral, scapuloperoneal, distal,
  limb girdle etc.
• genetically mediated progresssive disorders
  cycle of muscle necrosis, regeneration, fibrosis
  and replacement with fatty tissue. Mx -
  symptomatic
• Myotonic dystrophy
• Also genetic, characterised by myotonia (failure
  of muscle to relax after contraction) affects
  multipe m grps. Mx symptomatic.
• Inflammatory myopathy
• Eg polymyositis, inclusion body myositis,
  inflammatory myositis etc
• Involve inflammatory changes in muscle leading to
  weakness in affected distribution, necrosis etc.
  Mx try steroids, symptomatic

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Multifocal disorders

• Meningitis
• Usually infective activity in meninges fever,
  stiff neck (PNF), kernigs sign (pain on SLR),
  LOC. Mx antibiotics if bacterial, symptomatic.
• Poliomyelitis
• Acute viral infection of anterior horn cells of
  Sc and motor nuclei of brain stem initial SS
  of illness then developingweakness distributed as
  per infection. Long term rehab for persistent
  weakness/paralysis.
• Post polio syndrome
• Development of sequelae up to 30yrs post original
  PM fatigue, myalgia, further weakness/muscle
  atrophy. Mx symptomatic

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Multi-focal cont

• Epilepsy
• Paroxysmal, uncontrolled discharge of neurons
  within CNS range from major convulsions to
  brief period of reduced awareness. Dx via EEG
• Partial ie focal / local simple, complex if LOC
• Generalised absences (petit mal), myoclonic,
  clonic (shaking), tonic (sustained), atonic
• Mx control cause, medication, surgery (last
  resort). During seizure first aid principles.

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Multifocal contin.

• Dementia
• Progressive deterioration of intellect,
  behaviour, personality diffuse disease of
  brain. Classification based on cause or site
• Alzheimers, multi-infarct (cerebrovascular),
  Neurodegenerative (Huntingtons, PD), Infective
  (CJD), nutritional (Wernicke Korsakoff) etc
• Mx directed at cause, symptomatic
• Nutritional disorders
• Eg Wernicke Korsakoff thiamine deficiency from
  poor nutrition usually related to alcoholism
  ataxia, abnormal eye movement, confusion. Mx-
  treat deficiency, symptomatic
• B12 deficiency subacute degeneraton of the
  spinal cord. Mx cause of deficiency
• Nutritional polyneuropathy deficiencies of the
  Vit B complex can result in peripheral nerve
  damage (eg beri-beri).

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Multifocal contin.

• AIDS
• HIV affects lymphocytes and microglia. AIDS is
  the endstage of chronic infection.
• Neuro SS affect 80 include cerebral tumours,
  dementia, encephalitis, meningitis, peripheral
  neuropathy, myelopathy etc.
• Mx highlyactive anti-retroviral therapy
  (HAART), symptomatic

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Multifocal contin.

• Multiple Scerosis see N/S lecture notes
• Motor Neuron Disease / Amytrophic Lateral
  Sclerosis (ALS synonymous to MND)
• progresive degeneration of upper and lower motor
  neurons, cause unknown
• Asymmetric weakness, wasting, dysphagia,
  dysarthria usually fatal
• Mx symptomatic and support
• Spinal Muscular Atrophy
• Inherited, degeneration of ant horn cells
  symmetrical weakness and wasting (infant and
  adult onset types) adult better prognosis.
• Mx - symptomatic