Decreased mental status and central D emyelinating emergencies
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Transcript of Decreased mental status and central D emyelinating emergencies
DECREASED MENTAL STATUS AND CENTRAL DEMYELINATING EMERGENCIES
Bradley OstermanPediatric neurology – R4Summer lecture series 2012
PLAN Introduction
Consciousness & impaired consciousness
Coma Etiologies of coma
DD of coma-like states
Demyelinating emergencies ADEM
NMO
Demyelinating w/u of a CIE
INTRODUCTION Patient brought into the ER unconscious
First reflex
The « ABC »
But don’t forget about the « D » !
Disability
CONSCIOUSNESS What does it mean to a neurologist?
Product of two basic brain functions (1) Arousal – wakefulness
ARAS (ascending reticular activating system) (2) Awareness
encompasses multiple functions - attention, memory & executive function
Impaired consciousness can result from derangement in :
(1) arousal,
(2) awareness,
(3) or both, in varying degress
IMPAIRED CONSCIOUSNESS There is a wide spectrum
Avoid confusing, imprecise terms such as : Somnolence, stupor, obtundation, lethargy
Use specific statements to describe the patient’s LOC: Ex. « patient responds to painful sternal rub by grimacing & moving R arm »
GLASCOW COMA SCALE
Has its limitations.
Originally designed for TBI
GCS 12-14 – mild alteration of
consciousness
GCS 9-11 – moderate
GCS 8 and below – severe
COMA The term « coma » is actually a specific state of consciousness
characterized by : A complete absence of both (1) arousal & (2) awareness For ≥ 1 hour Absence of normal sleep-wake cycle No spontaneous or stimulus-induced eye-opening No purposeful mvts
Be familiar with the DD of coma-like conditions
ETIOLOGIES OF COMA (1) Direct insult to the CNS
Structural causes Supratentorial (ie. Brain tumor, hemorrage, encephalitis)
Subtentorial (ie. Midbrain infarction, acute demyelination of brainstem )
Seizures (NC SE)
Hydrocephalus/raised ICP
Traumatic brain injury (TBI)
(2) Metabolic/toxic causes
DD OF COMA-LIKE CONDITIONS
Condition Arousal Awareness Motor function Breathing Sleep-Wake
Locked-in syndrome N N
No (exc. eye blinking & vertical
eye mvt) N N
Akinetic mutism N partially present decreased mvts N N
Minimally conscious state N
partially present (minimally)
nonpurposeful (or very limited) N N
Vegetative state N absent nonpurposeful N N
Coma absent absent nonpurposeful N absent
Brain death absent absentNo (exc. spinal
reflexes) absent absent
LOCKED-IN SYNDROME Occurs with brainstem injuries sparing the midbrain
Patients have normal (1) arousal & mostly intact (2) awareness, but have a severely limited ability to communicate due to paralysis of voluntary muscles & anarthria
Can be seen with : Pontine glioma Basilar artery occlusion Profound neuromuscular dysfunction (GBS, SMA, botulism,
organophosphate toxicity) Trauma
AKINETIC MUTISM State of profound apathy with partially intact awareness, and paucity and
slowness of voluntary mvts (1) Normal arousal, and (2) mostly intact awareness (normal attentive pursuit)
On the verge of initiating speech or motor activity (but never happens)
Seen with bilateral injuries to the midbrain, basal diencephalon, or inferior
frontal lobes, occuring in : Tumors or tumor resection (mainly posterior fossa) TBI Hydrocephalus CNS infections
MINIMALLY CONSCIOUS STATE Relatively new term
(1) Arousal present & (2) minimally present awareness
Patients capable of reproducible & purposeful (albeit very limited) motor
movements or affective behaviour Ex. following simple commands, reaching accurately for an object, crying or smiling in response to emotional stimuli
VEGETATIVE STATE Arousal present
Awareness absent (self & environment)
No voluntary or purposeful mvts
Preserved respiratory function & sleep-wake cycles
Including periods of spontaneous eye-opening
Intact brainstem & hypothalamic function
Considered permanent if lasts :
> 12 months after TBI or
> 3 months after non-traumatic brain injury
BRAIN DEATH Complete & irreversible loss of (1) brain and (2) brainstem
function, characterized by : Loss of consciousness
Loss of cranial nerve function
Loss of motor function
Loss of breathing activity
Loss of sleep-wake cycle
Specific criteria – complete brain death exam
DD OF COMA-LIKE CONDITIONS
Condition Arousal Awareness Motor function Breathing Sleep-Wake
Locked-in syndrome N N
No (exc. eye blinking & vertical
eye mvt) N N
Akinetic mutism N partially present decreased mvts N N
Minimally conscious state N partially present
nonpurposeful (or very limited) N N
Vegetative state N absent nonpurposeful N N
Coma absent absent nonpurposeful N absent
Brain death absent absentNo (exc. spinal
reflexes) absent absent
DEMYELINATING EMERGENCIES
ADEM (ACUTE DISSEMINATED ENCEPHALOMYELITIS)
An autoimmune-mediated inflammatory episode involving the CNS Usually monophasic (5-20% cases are multi-phasic)
Usually following an infection (or vaccination; 3-6% of cases) Up to 4 weeks prior to sx (gen. 1-20 days)
Children > adults (peak ages 5-8 y/o) Incidence 8/1,000,000; seasonal increase in spring & winter months Described equally in all racial, ethnic groups and genders (unlike MS)
Mortality rate – 5% Full recovery – 50-75% Average time to recovery – 6 months
ADEM – CLINICAL PRESENTATION Abrupt onset
With rapid progression – maximum deficits < 1 week (average 4.5 days)
Encephalopathy Mild to severe alteration in mental status (irritability to coma)
Convulsive seizures (25%)
Focal neuro aN Weakness, ataxia, visual aN, sensory aN, cranial nerve aN, sphincter dysfunstion
Constitutional sx H/A, No/Vo, malaise
ADEM – PHYSICAL EXAM Alteration in mental status (>90%)
Cranial nerve aN (35-50%) (w/ possible brainstem dysfunction)
Meningeal signs (20%)
Weakness (50-75%) Hemiparesis, diaparetic, generalized
Long tract signs (80%) Clonus, increased DTR, upgoing toes
Ataxia (35-60%)
Sensory deficits (15-20%) (w/ possible sensory level)
ADEM – MRI
ADEM – axial T2-weighted images
Large, T2-hyperintense, patchy, poorly circumscribed
ADEM – MRI
ADEM – sagittal cervical spine & axial T2-weighted brain images
Large, T2-hyperintense, patchy, poorly circumscribed
ADEM – MRI Typically involves the gray-white junction
ADC map – consistent w/ vasogenic edema
Gado-enhancing (30-90%)
Compared to MS Periventricular lesions (30-45%) and corpus callosum
lesions (20-25%) are less common in ADEM
Additional lesions found in: optic nerves, basal ganglia (30-40%), the thalamus (30-
40%), the brainstem (45-55%), the cerebellum (30-40%) &
spinal cord
ADEM – INVESTIGATIONS Lumbar puncture
leukocytosis (80%); N/elevated OP, protein often > 1.0; N glucose; absent OCB
CSF cultures, serologies typically negative
EEG – diffuse slowing
Work-up for other Demyelinating disorders & Mimics
ADEM – TREATMENT 1st line tx – high-dose IV corticosteroids
Methylprednisolone (Solumedrol) – 30 mg/kg/day x 5 days Up to max 1 G Solumedrol daily x 5 days (ie. Like in adults)
Followed by 3-6 weeks of tapering prednisone Less than 3 week taper has a higher risk of relapse
2nd line – IVIG and/or plasma exchangev(PLEX)
ADEM – EVOLUTION/CLASSIFICATION Monophasic (same acute episode)
With fluctuating/subsequent sx as long as the relapse is : < 3 months of onset < 1 month following steroid tx
Recurrent ADEM Relapse with identical sx ≥ 3 months or ≥ 1 month following steroid tx
Multi-Phasic Relapse with new features and change in mental status ≥ 3 months or ≥ 1 month of steroid tx MRI must show new areas of involvement & partial resolution of previous lesions
ADEM – FLOWCHART
NMO – NEUROMYELITIS OPTICA NMO or Devic’s disease
Idiopathic, inflammatory, necrotizing demyelination of the CNS
Simultaneous or successive involvement of : optic nerves & spinal cord
Mediated by anti-NMO-IgG antibodies Unlike MS, not T-cell mediated
Targets the protein aquaporin 4 in the cell membrane of astrocytes
Impaired water transport across the membrane leading to inflammatory demyelination
NMO – CLINICAL PRESENTATION Visual loss (painful & subacute)
Optic neuritis (ON)
Spinal cord dysfunction Transverse myelitis (TM)
weakness
sensory deficits (w/ level)
sphincter dysfunction
Unilateral ON (45%); simultaneous & bilateral ON (25-30%)
Isolated TM (10-15%)
Simultaneous ON & TM (10-15%)
NMO – DIAGNOSTIC CRITERIA
NMO – TREATMENT High-dose glucocorticod therapy
IVIG/PLEX Obtain sample for anti-NMO ab prior
Immunosuppressant therapy Ex. Imuran
NMO – PROGNOSIS High rate of recurrence (> 90%)
Relapse within first year (50%), and within 5 years (90%)
Relapse interval generally < 3 months
Deficits (ON/TM) tend to be severe & recovery incomplete Permanent leg paralysis and/or blindness in > 50%
DEMYELINATING (CIS) WORK-UP – AT MCH Serum
CBC, Glucose, Lactate, TSH, T4, vit B12, IgG index, VLCFA
ESR, CRP, ANA, dsDNA, APLA, ACE (vasculitic w/u)
Viral serologies (HIV, VDRL, HSV)
Lyme (serology +/- PCR)
CSF Cell count (WBC), Glucose, Protein, Lactate (on ice)
OCB (w/ serum IgG index)
Viral culture (enterovirus, CMV), Bacterial culture
Herpes PCR, Mycoplasma PCR
QUESTIONS?