Transcript File

Neural tube defects
 Neural tube defects (NTDs) are
common birth defects of the brain and
spinal cord that include anencephaly,
spina bifida (meningocele,
meningomyelocele).
 Deficiency of folic acid increases the
risk of neural tube defects, due to the
mutation of a gene for an enzyme that
is related with folic acid.
 The most common causes of neural
tube defects are insufficient folic acid in
the mother's diet, both before she
became pregnant and during the first
few weeks of pregnancy.
 Rx: Depends on severity of
complications
 Anencephaly- None
 Spina bifida, meningocele and
meningomyelocele- aggressive
surgical management
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BROWN SEQUARD SYNDROME
 Results from unilateral cord compression/ lateral
hemisection of spinal cord
 Aka- crossed hemiplegia
 Impaired pain and temperature sensation
 Impaired light touch and vibration and position sensation
 Increased tendon reflexes and extensor plantar response
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Brown-Séquard syndrome's symptoms:
* = Side of the lesion
1. Hypertonic paralysis
2. Spastic paralysis and
loss of vibration and
proprioception
(position sense) and
fine touch
3. Loss of pain and
temperature sensation
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• The hemisection of the cord results in a lesion of each of
the three main neural systems:
– the principal upper motor neuron pathway of the corticospinal
tract
– one or both dorsal columns
– the spinothalamic tract
• As a result of the injury to these three main brain pathways
the patient will present with three lesions:
– The corticospinal lesion produces spastic paralysis on the same
side of the body (the loss of moderation by the UMN).
– The lesion to fasciculus gracilis or fasciculus cuneatus results in
ipsilateral loss of vibration and proprioception (position sense)
as well as loss of all sensation of fine touch.
– The loss of the spinothalamic tract leads to pain and
temperature sensation being lost from the contralateral side
beginning one or two segments below the lesion.
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CENTRAL CORD SYNDROME:
• Involves gray matter and crossing of Spinothalamic
tract
• Motor weakness
• Dissociate sensory loss
• E.g:Syringiomyelia,Tumors
ANTERIOR 2/3rd SYNDROME:
•
•
•
•
Bilateral involvement of anterior spinal cord
Motor,sensory,Autonomic functions are lost
Posterior column spared
E.g: Vascular:Thrombosis of anterior spinal artery or
by tumors
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Patterns of sensory loss
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NON COMPRESSIVE SPINAL CORD
LESION
1. Vascular
2. Inflammatory
• Transverse myelitis
• Multiple Sclerosis
3.Development:Syringomyelia
4.Metabolic: Subacute combined
degeneration(Deficiency of Vit B12)
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Clinical differentiation:
Compressive
Non-Compressive
Bony
deformity/Tenderness
+
-
Root pain
+
-
Bladder and Bowel
involvement
Early
Late
Girdle like sensation
Present
Absent
Zone of Hyperesthesia
Present
Absent
Symmetry
Asymmetrical
Symmetrical
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CERVICAL SPONDYLOSIS
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Spondylosis :
– Spondylosis is a term referring to degenerative osteoarthritis of the joints
between the centra of the spinal vertebrae and/or neural foraminae
– When the space between two adjacent vertebrae narrows, compression of
a nerve root emerging from the spinal cord may result in radiculopathy
• sensory and motor disturbances, such as severe pain in the neck, shoulder, arm,
back, and/or leg, accompanied by muscle weakness.
– Less commonly, direct pressure on the spinal cord (typically in the cervical
spine) may result in myelopathy
• characterized by global weakness, gait dysfunction, loss of balance, and loss of
bowel and/or bladder control.
– The patient may experience a phenomenon of shocks (paresthesia) in
hands and legs because of nerve compression and lack of blood flow.
– If vertebrae of the neck are involved it is labeled as Cervical Spondylosis.
– Lower back Spondylosis is labeled Lumbar Spondylosis.
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Physical signs of compression of
cervical roots
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• Investigations
– Plain X ray cervical spine
Antero-posterior
Lateral
– In severe cases MRI of the cervical spine
• Management of cervical radiculopathy
– Analgesic
– Cervical collar
– Surgery if deficit is severe or conservative
therapy fails.
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Cervical collar
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Cervical spondylotic myelopathy :
• Progressive, gradual onset
• Prone to have hyperextension injury of the
cervical cord
• Spastic quadriparesis with loss of sensation and
ultimately, involvement of bowel and bladder.
• Investigation of choice is MRI
• Treatments
– conservative
– surgery disc resection, vertebral lamina
resection.Surgery sometimes leads to acute
deterioration.
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Lumbar disc herniation :
• Common problem in middle aged and elderly.
• Precipitated by trauma or lifting a heavy weights when
spine is flexed.
• Onset may be sudden or gradual, Constant aching pain
in the lumbar region and may radiate to the buttock,
thigh, calf and foot.
• Pain is exacerbated by coughing or straining and may be
relieved by lying flat.
• SLRT (straight leg rising test) may be positive (positive
Lasegue’s sign)
• MRI is the investigation of choice
• Management :conservative or surgery
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Case
• A 25 year old male was brought to Emergency
department. Status- Post motor vehicle accident.
• Emergency doctor does ABC management
• On CNS examination
– Motor
– B/L Lower extremity weakness ~4/5
– B/L With hyperreflexia
– Cranial nerves
– Intact
– Sensory
– Pain and temperature- lost in lower extremities
– Vibration and position- intact
– Light touch- intact
– What is the likely diagnosis? Why?
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Syringomyelia
• Cavitation of spinal cord
• Fluid-filled cavity (or cavities) develops near the
centre of the spinal cord, usually in the cervical
segments
• The expanding cavity disrupts second-order
spinothalamic neurons
• May extend laterally to damage the anterior horn
cells, and may compress the long fiber tracts.
• It is assumed that the disturbed CSF dynamics cause
the development of the syrinx but the mechanism is
not clear.
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• Communicating Associated with Arnold
Chiari malformation
• Noncommunicating secondary to spinal
cord trauma
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Syringomyelia
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Clinical features
• Pain in the neck or shoulder is common and patients
may seek advice because of sensory loss in the upper
limbs
• Dissociated sensory loss (impaired pain and
temperature sensation with preservation of dorsal
column modalities- intact sensation of light touch)
• Loss of protective sensory function leads to tropic
lesions such as painless burns or ulcers on the hands
• Ultimately sensory loss in all four limbs with UMN signs
below the lesion and LMN sign at the level of lesion.
• Investigation is MRI
• Treatment is surgical.
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Subacute combined degeneration
•
•
•
•
•
•
Occurs with vitamin B12 deficiency
Distal paresthesias
Weakness of extremities
Spastic paresis
Ataxia
In classical case Deficit of vibration and proprioception
with pyramidal signs (Plantar extension and hyperreflexia)
• Investigation Serum Vitamin B12 level (Low)
• Rx Vitamin B12 therapy
– 250 µg to 1 mg of B12 daily
– S/C or I/M injections of Vit B12 weekly for ~20 weeks followed
by lifelong
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Anterior Spinal artery infarct
• Acute flaccid paralysis which evolves into
flaccid paresis over days to weeks
• Loss of pain and temperature sensation
• Sparing of vibration and position sense
• (Posterior columns are supplied by Posterior
spinal artery)
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Transverse myelitis:• It affects one to five persons per million.
• Transverse myelitis is an acute inflammatory
condition usually secondary to viral illness or recent
vaccination may be with multiple sclerosis and
other inflammatory and vascular disorders (eg:syphilis)
• where there is a progressive sensory loss and
weakness.
• Transverse myelitis (TM) is an uncommon
neurological syndrome caused by inflammation
(includes swelling, pain, heat, and redness) of the
spinal cord.
• Characterized by weakness, back pain, and bowel
and bladder dysfunction.
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Clinical feature:
• Though non compressive, it presents as compressive
myelopathy
• Features depend on spinal segment involved
• Commonly involved: Thoracic segments
• Acute/ Subacute course
• Paresthesia
• Motor weakness: Paraplegia, UMN type
• Sensory loss
• Bladder involvement
• Acute stage: Neural shock
• May be difficult to differentiate with GBS
• Similar symptoms may be present in multiple sclerosis
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 Investigations:
• MRI of spinal cord
 Treatment:
1. Steroid: Methylprednisolone IV for 3 days
Followed by Prednisolone 1mg/Kg/Day for several
weeks
2. Other Rx:
• Physiotherapy
• Care of Bladder and bowel
• Prevention of DVT
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Poliomyelitis:
• Poliomyelitis results from a relatively selective
destruction of lower motor neurons in the
anterior horn cell of spinal cord by polio virus.
• The disease causes Flaccid paralysis of muscles
with accompanying Hyporeflexia and
Hypotonicity.
• Some patients may recover most
function,whereas others progress to muscle
atrophy and permanent disability.
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PARTIAL SEIZURES
Simple partial seizure :
 Not associated with loss of consciousness and Limited to part
of the body
 Denotes focal pathology in brain/involve only one hemisphere
 Typically associated with structural abnormalities of brain such
as scars,tumors,AV malformation or focal areas of
inflammation
 Can be Motor/Sensory/Autonomic/Psychomotor
 In typical motor type there is clonic ( repetitive flexion and
extension) movement at the rate of 2-3 Hz.
 Other features of partial motor seizure are
 Jacksonian March
 Todd’s paralysis
 Epilepsia partialis continua
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 Partial sensory seizures-- somatic sensation like
paraesthesia or tingling sensation /electric sensation
in the contralateral face and limbs
 Partial visual seizures—visual hallucinations such as
ball of light,flashes of light and hallucinations of faces
and scenes
 Partial psychic seizures—
• Sensation of falling /vertigo
• There may be olfactory or auditory hallucinations,
undue familiarity (déjà vu), feeling of unreality
(jamais vu)
 Autonomic seizures-- flushing, sweating, pilorection,
epigastric discomfort, nausea
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Complex partial seizures:
--Usually arises from temporal lobe and less
frequently from frontal lobe
Psychomotor(Temporal lobe) seizures:
-- Associated with altered consciousness
--Associated with loss of posture and tone
--Aura may be present
--Patients stop what he /she is doing and stares
blankly, often making rhythmic smacking
movements of lips/picking at their clothes
--After few minutes patients gains consciousness
but may be drowsy
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GENERALIZED SIEZURES
 Involving diffuse regions of both hemisphere,simultaneously and
synchronously
 Results from cellular,biochemical or structural abnormalities
with widespread distribution
Absence seizures :
 Petitmal epilepsy
 Brief/Transient
 Commonly seen in childhood
 During an attack child stops activity
 Vacant stares, may blink or roll up the eye and fails to respond to
commands
 Do not cause loss of posture
 Attacks lasts for few seconds
 More frequent
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• Tonic seizures: Tonic tightening of limbs along with
loss of consciousness
• Clonic seizures: Clonic movements of limbs i.e
rhythmic flexion and extension of limbs
• Myoclonic seizures: It consists of single or multiple
myoclonic jerks involving one part of the body or
entire body.
• Atonic seizures: Characterized by sudden loss of
postural muscle tone,lasting for 1-2 secs,with brief
impairment of consciousness
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Generalized tonic-clonic seizure :
 Prodromal phase: Hours or days before attack,unease,irritability
 Aura: Preceded by partial seizure,and patients usually anticipates
that seizure will occur.These feeling may be olfactory
hallucination,epigastric discomfort,jerking of one limb
 Tonic phase: There is tonic contractions of the muscles,there is
flexion and adduction of arms and extension of legs, patient goes
rigid,presence of cyanosis and loss of consciousness. Lasts for 1030 sec
 Clonic phase: This period does not last for more than 1 min.There
is violent jerky movements of face and limbs. Patient may sustain
injuries like tongue bite and incontinence.
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 Post-ictal phase : Unresponsiveness/Deep
unconsciousness, muscular flaccidity, salivation, loss
of corneal reflex,extensor plantar response.Lasts from
few minutes to several hours
 Patient gradually regains consciousness over minutes
to hours.
 There may be
headache,vomiting,confusion,drowsiness,fatigue,
muscle ache
 Recover within 1-2 days
 In EEG tonic phase has low voltage fast activity
followed by high voltage polyspike discharges, spike
and wave.
 In post-ictal phase there is diffuse slowing
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•
•
•
•
•
D/D of seizure
TIA
Panic attacks
Syncope
Cardiac dysrhythmias
Metabolic ,Sleep disorders,Movement disorders
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• Pseudo seizures:
 Used to denote Hysterical conversion reactions
 Attacks mimic epileptic seizures
 Characterized by an asynchronous thrashing of the
limbs,which increases if restraints are imposed.
 There is no post ictal phase
 EEG is normal
 Increase prolactin level after 15-30 mints of true tonicclonic seizure while unchanged in Pseudoseizure
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Anti epileptic drugs ( Anticonvulsant)
• Phenytoin
– Membrane stabilizing agent (↓Na and Ca influx)
– Dose 3-6 mg/Kg/d
– Adverse effects: gum hypertrophy, hirsutism, glucose
intolerance, megaloblastic anemia, lymphadenopathy,
nausea and vomiting, ataxia, nystagmus.
– Teratogenic (fetal hydantoin syndrome)
• Carbamazepine
– Membrane stabilizing agent (↓Na influx)
– Dose 15-35 mg /Kg/d
– Adverse effects: ataxia, dizziness, diplopia, vertigo,
aplastic anemia, leukopenia, hepatotoxicity.
– Safe in pregnancy
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• Phenobarbitone
– MOA exactly unknown.may be involves in
potentiation of GABA.
– Dose 1-4 mg/Kg/d
– Adverse effects: sedation, ataxia, nystagmus, vertigo,
agitation , confusion, skin rash.
• Valproic acid
– Potentiation of GABA.
– Dose 20-60 mg/Kg/bid-qid
– Adverse effects: ataxia, sedation, tremor,
hepatotoxicity, alopecia
– Drug of choice in myoclonic seizure
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• Ethosuximide
– Reduces propagation of abnormal electrical activity
in the brain
– Dose 20-40 mg /Kg/ daily to bid
– Ataxia, lethargy, headache, skin rash, GI
irritation,bone marrow suppression
– Drug of choice for absence seizures
• Benzodiazepines
– Clonazepam is effective in myoclonic and absence
seizures.
– Diazepam- immediate treatment of any seizure.
– Good safety profile.Sedation, drowsiness occurs in
high dose.
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Gabapentin and Lamotrigine
• Gabapentin
– is an analogue of GABA.
– Effective in focal onset seizures
– Side effects are sedation, dizziness, ataxia, GI
irritation.
– Dose 900-2500/d
• Lamotrigine
– inhibits exitatory neurotransmitters like glutamate
and aspartate, blocks sodium channels.
– Broad spectrum, dose is 150-500mg/d BID
– Dizziness, diplopia, sedation, ataxia are adverse
effects.
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EEG (Electro-Encephalogram)
• An Electroencephalogram (EEG) is a test commonly
performed to look at the electrical activity of the brain
i.e. the brain waves or how the brain is functioning.
• It is a simple, painless test and involves no needles or
injections.
• In normal subjects, 4 types of waves
• In ascending order of frequency
–
–
–
–
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δ.less than 4 waves per second
θ.4-6 waves per second
α.7-13 waves per second
β.more than 13 waves per second
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EEG cap
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EEG (Electro-Encephalogram)
Delta waves
• Location:frontally in adults,
posteriorly in children; high
amplitude waves
• subcortical lesions
• diffuse lesions
• metabolic encephalopathy
hydrocephalus
• deep midline lesions
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Theta waves
• Location:Found in locations
not related to task at hand
• focal subcortical lesions
• metabolic encephalopathy
• deep midline disorders
• some instances of
hydrocephalus
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EEG (Electro-Encephalogram)
Alpha waves
• Location: posterior regions
of head, both sides, higher
in amplitude on dominant
side.
• coma
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Beta waves
• Location: both sides,
symmetrical distribution,
most evident frontally; low
amplitude waves
• benzodiazepines
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EEG (Electro-Encephalogram)
Gamma waves
• Location:Somatosensory
cortex
• A decrease in gamma band
activity may be associated
with cognitive decline,
especially when related the
theta band
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Normal EEG
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Grossly abnormal EEG
•
•
•
•
Spikes and waves
Slowing of waves, appearance of delta wave
Triphasic slow waves
Electrocerebral silence
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Spikes and waves
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Diffuse encephalopathy, polymorphic delta wave
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Clinical uses
• to distinguish epileptic seizures from other types of
spells, such as psychogenic non-epileptic seizures,
syncope (fainting), sub-cortical movement disorders
and migraine variants.
• to differentiate "organic" encephalopathy or delirium
from primary psychiatric syndromes such as catatonia
• to serve as an adjunct test of brain death
• to prognosticate, in certain instances, in patients with
coma
• to determine whether to wean anti-epileptic
medications
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