Chapter 49 - Neurologic Disorders

Cerebrospinal fluid (CSF)

a colorless, alkaline fluid with a specific gravity of approximately 1.004 to 1.008, containing traces of protein, glucose, lymphocytes, and body salts.

Opening pressure

Newborns: 8-10 cm H₂O; children: 10–18 cm H₂O

Lowered pressure

usually indicates there is subarachnoid obstruction in the spinal column above the puncture site.

Elevated pressure

suggests intracranial compression, hemorrhage, or infection.

Appearance

Clear and colorless

Cloudy (CSF)

indicates possible infection with an increased number of white blood cells (WBCs).

Reddened (CSF)

probably because of red blood cells (RBCs).

Cell count

0–8/mm³

Granulocytes (in CSF)

suggest cerebrospinal fluid (CSF) infection.

Lymphocytes (in CSF)

suggest meningeal irritation and inflammation.

Protein (CSF)

15–45 mg/100 ml

Elevated protein count (>45/100 ml)

occurs if RBCs are present.

Glucose (CSF)

60%–80% of serum glucose level

Bacterial meningitis

causes a marked decrease in CSF glucose.

Viral infections

do not cause a decrease in CSF glucose and may occasionally cause a slight increase.

Albumin/globulin (A/G) ratio

8:1

Increased A/G level

suggests infection or a neurologic disorder.

Stereognosis

the ability of a child to recognize an object by touch; it is a test of sensory interpretation.

Graphesthesia

the ability to recognize a shape that has been traced on the skin.

Kinesthesia

the ability to distinguish movement.

Lumbar puncture

the introduction of a needle into the subarachnoid space (under the arachnoid membrane) at the level of L4 or L5 to withdraw CSF for analysis.

Ventricular tap

In infants, CSF may be obtained by a subdural tap into a ventricle through the anterior fontanelle. A small space on the scalp over the insertion site is shaved or clipped, and the area is prepared with an antiseptic.

Cerebral angiography

an X-ray study of cerebral blood vessels that involves the injection of a contrast material into the femoral or carotid artery.

Myelography

the X-ray study of the spinal cord following the introduction of a contrast material into the CSF by lumbar puncture.

Computed tomography (CT)

involves the use of X-rays to reveal densities at multiple levels or layers of brain tissue.

Brain scan

For a brain scan, a radioactive material is injected intravenously, and after a fixed time during which the injected material is deposited in cerebral tissue, radioactivity levels over the skull are measured.

Positron emission tomography (PET)

involves imaging after injection of positron-emitting radiopharmaceuticals into a vein.

Echoencephalography

involves the projection of ultrasound (high-frequency sound waves above the audible range) toward the child’s head or spinal cord (a type of ultrasound).

Electroencephalography (EEG)

a noninvasive measurement of the brain’s electrical fields

Increased intracranial pressure (ICP)

not a single disorder but a group of signs and symptoms that occur with many neurologic disorders.

Pulse pressure

the gap between the systolic and diastolic blood pressures.

Doll’s eye reflex

If a child lies supine and you turn his or her head gently but rapidly to the right, the eyes will normally turn toward the left, and vice versa.

Decorticate posturing

the child’s arms are adducted and flexed on the chest with wrists flexed, hands fisted; the lower extremities are extended and internally rotated; the feet are plantar flexed.

Decerebrate posturing

characterized by rigid extension and adduction of the arms and pronation of the wrists with the fingers flexed; the legs are held extended with the feet plantar flexed.

Cerebral perfusion pressure (CPP)

the amount of cerebral blood flow available to the brain.

Mean arterial pressure (MAP)

determined by subtracting the diastolic blood pressure (DBP) level from the systolic blood pressure (SBP) level, then dividing the result by 3, and adding that sum to 80.

Neurocutaneous syndromes

characterized by the presence of skin or pigment disorders with CNS dysfunction.

Sturge-Weber syndrome (encephalofacial angiomatosis)

a congenital port-wine birthmark on the skin of the upper part of the face that follows the distribution of the first division of the fifth cranial nerve (trigeminal nerve).

Neurofibromatosis (von Recklinghausen disease)

the unexplained development of subcutaneous tumors.

Cerebral palsy (CP)

a group of nonprogressive disorders of upper motor neuron impairment that result in motor dysfunction.

Spastic Type

Spasticity is excessive tone in the voluntary muscles that results from loss of upper motor neurons.

Hemiplegia

spastic involvement affecting both extremities on one side.

Quadriplegia

spastic involvement affecting all four extremities.

Diplegia or paraplegia

spastic involvement primarily affecting the lower extremities.

Pseudobulbar palsy

impaired speech in a child with quadriplegia.

Dyskinetic or Athetoid type

involves abnormal involuntary movement (athetoid means “wormlike”).

Ataxic type of CP

characterized by an awkward, wide-based gait and inability to perform fine coordinated motions.

Mixed type of CP

symptoms of both spasticity and athetoid or ataxic and athetoid movements.

Bacterial meningitis

infection of the cerebral meninges.

Group B streptococcal infection

a major cause of meningitis in newborns.

Encephalitis

an inflammation of brain tissue and, possibly, the meninges as well.

Reye syndrome

acute encephalopathy with accompanying fatty infiltration of the liver, heart, lungs, pancreas, and skeletal muscle.

Guillain-Barré syndrome

an inflammatory disease that is more frequently noted in males than females. Both motor and sensory portions of peripheral nerves are affected. Inflammation of the nerve fibers apparently causes temporary demyelization of the nerve sheaths.

Botulism

occurs when spores of Clostridium botulinum colonize and produce toxins in the intestine.

Carpal tunnel syndrome

compression of the median nerve that passes through the wrist and is rare in children

Facial palsy (Bell palsy)

facial paralysis of the seventh (facial) cranial nerve, the nerve that innervates the muscles of facial expression.

Seizure

an involuntary contraction of muscle caused by abnormal electrical brain discharges.

Epilepsy

recurrent seizures (preferred term to avoid stigma).

Infantile spasms

a form of generalized seizure often called “salaam” or “jackknife” seizures, characterized by very rapid movements of the trunk with sudden strong contractions of most of the body.

Hypsarrhythmia

chaotic discharge on an EEG tracing in infants with spasms.

Febrile seizures

seizures associated with high fever (102° to 104°F [38.9° to 40.0°C]).

Postictal state

drowsy state after a seizure.

Complex partial (psychomotor or temporal lobe) seizures

seizures that vary greatly in extent and symptoms, often beginning with a sudden change in posture or automatisms.

Automatisms

complex purposeless movements, such as lip smacking, fumbling hand movements, intense running, or screaming.

Partial (focal) seizures

originate from a specific brain area. A typical sign is a motor sign begin in the fingers and spreads.

Absence seizures

one form of generalized seizures, consisting of a staring spell that lasts for a few seconds.

Tonic–clonic seizures

generalized seizures usually consisting of three stages: a prodromal period, an aura, tonic–clonic stage, and postictal stage.

Aura

reflects the portion of the brain in which the seizure originates (e.g., smelling odors, seeing lights).

Tonic stage

all muscles of the body contract, extremities stiffen, the face distorts, air is pushed through the glottis producing a guttural cry.

Clonic stage

muscles of the body rapidly contract and relax, producing quick, jerky motions.

Postictal period

sound sleep for 1 to 4 hours following tonic–clonic seizure.

Status epilepticus

a seizure that lasts continuously for longer than 30 minutes or a series of seizures from which the child does not return to the previous level of consciousness.

Breath holding

a phenomenon that occurs in young children when they are stressed or angry, leading to cyanosis and momentary unconsciousness.

Tension or stress headache

a dull, steady pain across the forehead, temporal area, or back of the neck caused by muscle contraction.

Migraine headache

a specific type of headache that may begin with an aura or visual disturbance, followed by unilateral intense throbbing pain.

Spinal cord injury without radiologic abnormality (SCIWORA) syndrome

spinal cord injury without visible fracture on X-ray.

Spinal shock syndrome

loss of autonomic nervous system function immediately after spinal injury, leading to loss of motor function, sensation, reflex activity, and flaccid paralysis.

Autonomic dysreflexia

powerful sympathetic reflex reaction in spinal cord injury, causing extreme hypertension, tachycardia, flushed face, and severe occipital headache.

Upper motor neurons

nerve pathways of the brain and descending tracts (between brain and anterior horn).

Lower motor neurons

nerve pathways in anterior horn cells and spinal/peripheral nerves (between anterior horn and point of innervation).

Ataxia

failure of muscular coordination or irregularity of muscle action.

Ataxia-telangiectasia

a rare, inherited disorder, transmitted as an autosomal recessive trait attributable to defecting chromosome 11 and a primary immunodeficiency disorder that results in progressive cerebellar degeneration.

Telangiectasias

red vascular markings on conjunctiva and skin.

Friedreich ataxia

characterized by a progressive loss of coordination and balance with a milestone of becoming fully wheelchair bound as the disease progresses.

Choreoathetosis

rapid, purposeless movements.

Headache

results because of meningeal or vascular irritation, not from the brain itself because brain tissue is insensitive to pain.

Spinal Cord Injury

Results when the spinal cord becomes compressed or severed by the vertebrae; further cord damage can result from hemorrhage, edema, or inflammation at the injury site as the blood supply becomes impeded.