[Localization']

• Isolated cranial nerve abnormalities( single or multiple)

• Crossed weakness (upper motor neuron pattern) and sensory abnormalities of head and limbs

[LOCALIZATION]

• Back pain or tenderness

• Weakness1 and sensory abnormalities sparing the head

• Mixed upper and lower motor neuron findings

• Sensory level

• Sphincter dysfunction

[LOCALIZATION]

• Back pain or tenderness

• Weakness or sensory abnormalities following root distribution

• Loss of reflexes

[LOCALIZATION]

• Mild or distal limb pain

• Weakness2 or sensory abnormalities following nerve distribution

• Stocking or glove distribution of sensory loss

• Loss of reflexes

[LOCALIZATION]

• Bilateral proximal or distal weakness

• Sparing of sensation

Level of Consciousness

• Awake, fully aware and responsive

• Normal waking consciousness

Level of Consciousness

• Responds when spoken to, may drift to sleep if no stimulation

• Some degree of inattentiveness and disorientation = "Clouding of consciousness"

Level of Consciousness

• May awaken to voice but is minimally responsive when doing so

• Inability to sustain a wakeful state without the application of external stimuli

Level of Consciousness

• Difficult to rouse, may groan or become restless to brief pain

• Can be roused only by vigorous and repeated stimuli

Level of Consciousness

• Patient is unresponsive or may show abnormal response voice or pain

• Incapable of being aroused by external stimuli

Demyer's Level of Depressed Consciousness

Level 1

Demyer's Level of Depressed Consciousness

Level 2

Patient can be aroused to a normal level of awareness

emyer's Level of Depressed Consciousness

Level 3

Patient can be aroused to some degree, but cannot reach or sustain normal level of consciousness → Lethargy

Demyer's Level of Depressed Consciousness

Level 4

Patient cannot be aroused

ASSESING THE EYE MOVEMENTS

Horner's syndrome

Damaged sympathetic

ASSESING THE EYE MOVEMENTS

Opiates

Organophosphates

Pontine lesions

Thalamic lesions

ASSESING THE EYE MOVEMENTS

Uncal herniation

Midbrain lesions

ASSESING THE EYE MOVEMENTS

Hypoxic Brain injury

Bilateral midbrain lesion

Sympathomimetic drugs

Anticholinergic drugs

ASSESING MOTOR TONE

Chorea and Hemiballismus

ASSESING MOTOR TONE

More likely due to global hypoxic injury

Pathophysiology

Lesion destroys or compresses brainstem arousal areas, either directly or secondary to more distant expanding mass lesions

Pathophysiology

Arousal centers poisoned or critical substrates depleted

Clinical Feature: Respiratory pattern

• Irregular, especially Cheyne-Stokes or ataxic breathing

• Also with selected stereotypical patterns like "apneustic" respiration (peak inspiratory arrest) or central hyperventilation

• If regular, may be normal or hyperventilation.

• If irregular, usually Cheyne-Stokes

Clinical Feature: Respiratory pattern

• If regular, may be normal or hyperventilation.

• If irregular, usually Cheyne-Stokes

Clinical Feature: Pupillary size and reaction

• Unequal or unreactive to light (fixed)

• Midposition, fixed: suggests midbrain compression

• Dilated, fixed: suggests compression of CN III from herniation

Clinical Feature: Pupillary size and reaction

• Equal, reactive to light. If pinpoint from opiates or cholinergic, you may need a magnifying glass to see the reaction

• May be unreactive if fixed and dilated from anticholinergics or hypothermia

Clinical Feature: Level of consciousness

Changes before pupils change

Clinical Feature: Level of consciousness

Changes after pupils change

Assessment of Level Consciousness (Bates')

Level 1: Alertness

patient opens the eyes, looks at you, and responds fully and appropriately to stimuli (arousal intact)

Assessment of Level Consciousness (Bates')

Level 2: Lethargy

The patient appears drowsy, but opens the eyes and looks at you, responds to questions, and then falls asleep.

Assessment of Level Consciousness (Bates')

Level 3: Obtundation

opens the eyes and looks at you but responds slowly and is somewhat confused. Alertness and interest in the environment are decreased.

ssessment of Level Consciousness (Bates')

Level 4: stupor

he stuporous patient arouses from sleep only after painful stimuli. Verbal responses are slow or even absent. The patient lapses into an unresponsive state when the stimulus ceases. There is minimal awareness of self or the environment.

Assessment of Level Consciousness (Bates')

Level 5: Coma

A comatose patient remains unarousable with eyes closed. There is no evident response to inner need or external stimuli.

Pupils in comatose patients

(1-2.5 mm)

→ Damage to the sympathetic pathways in the hypothalamus

→ Metabolic encephalopathy, a diffuse failure of cerebral function that has many causes, including drugs

→ Light reactions are usually normal.

Pupils in comatose patients

(<1 μμ)

→ Hemorrhage in the pons

→ Effects of morphine, heroin, or other narcotics. ▪ Opiate poisoning

→ Light reactions may be seen with a magnifying glass

Pupils in comatose patients

• Pupils that are in the midposition or slightly dilated (4-6 mm)

• Fixed to light

• suggest structural damage in the midbrain

Pupils in comatose patients

→ severe anoxia and its sympathomimetic effects

▪ seen after cardiac arrest

→ Atropine-like agents, phenothiazines, or tricyclic antidepressants

→ supratentorial mass with uncal herniation

Pupils in comatose patients

→ Herniation of the temporal lobe

▪ compression of the oculomotor nerve and midbrain

▪ supratentorial mass with uncal herniation

Pupils in comatose patients

Cocaine, amphetamine, LSD, or other sympathetic nervous system agonists.

A single large pupil Pupils in comatose patients

commonly seen in diabetic patients with infarction of CN III

Ocular Movements/Reflexes

Doll's eye movement

-Helps assess brainstem function in the comatose patient

Holding the upper eyelids open so that you can see the eyes, turn the head quickly, first to one side and then to the other

Ocular Movements/Reflexes

testing of brainstem function

usually not performed in an awake patient

• Make sure the eardrums are intact and the ear canals are clear.

Ocular Movements/Reflexes: Oculocephalic reflex

As the head is turned in one direction, the eyes move toward the opposite side is a response with an intact brain stem (T or F)

Ocular Movements/Reflexes: Oculovestibular reflex

Eyes drift toward the irrigated ear is a response with brain injury (T or F)

Ocular Movements/Reflexes: Oculocephalic reflex

• the ability to move both eyes to one side is lost

• suspicious for a lesion of the midbrain or pons

These are responses with a brainstem injury (T or F)

Ocular Movements/Reflexes: Oculovestibular reflex

• Νo response

This is a response with an intact brainstem (T or F)

Test used in the absence of any respiratory effort, even after fully oxygenating the patient and then allowing the pCO2 to rise to 50-60mmHg

Abnormal Posturing

Rigidity with arms inwardly rotated

• Brainstem problem

• Due to exaggeration of reflexes normally relied upon to defeat gravity when standing upright

• Posture may occur spontaneously or only in response to external stimuli such as light, noise, or pain

Abnormal Posturing

• Early

• Sudden unilateral brain damage

• Corticospinal tract

→ one-sided paralysis

→ flaccid early in its course

→ Spasticity will develop later

• Paralyzed arm and leg are slack

• Fall loosely

• Without tone when raised and dropped to the bed

Abnormal Posturing

Spontaneous movements or responses to noxious stimuli are limited to the opposite side

• Leg may lie externally rotated → One side of the lower face may be paralyzed

• Cheek puffs out on expiration

• Both eyes may be turned away from the paralyzed side

Abnormal Posturing

• Assume a "pugilistic" pose, with arms flexed as if ready to commence a boxing match

• Cerebral problem (Lesion above the brainstem)

• Postural implies a destructive lesion of the corticospinal tracts within or very near the cerebral hemisphere

Pupils in comatose patients

commonly seen in diabetic patients with infarction of CN III