CENTRAL NERVOUS SYSTEM DISORDERS

By; Mohammed Ussif Kaku

Table of Content

Anatomy Physiology CNS disordersI. Cerebral palsyII. Febrile ConvulsionsIII. Epilepsy

Anatomy of CNS

The central nervous system consist of the BRAIN & SPINAL CORD.

Physiology of CNS

Spinal cord - conducts sensory information to the brain - conducts motor information to the effector organs - serves as a simple regulatory centre (reflexes) - damage of the spinal cord breaks down the

connection between periphery and higher centres – serious consequences

• Brain the brain is the center of activity that integrates this information, initiates responses, and makes us the individuals we are.

- subcortical level - control of involuntary and subconscious functions, emotions

CEREBRAL PALSY

Cerebral palsy is the most common congenital physical handicap, with abnormalities of motor control caused by damage to the brain early in the course of development.

Cerebral palsy (CP) is a permanent nonprogressive neuromuscular disorder caused by damage to the immature brain.

CP is caused mainly by hypoxia, trauma, infection or hyperbilirubineamia (high amnts of bile pigment, bilirubin in the blood), genetic factors may involved.

ETIOLOGY

All the conditions that can cause damage to the

cognitive areas of the brain with resultant mental

retardation (MR) can also affect the motor areas of

the brain and result in cerebral palsy. These include:

Prenatal Prematurity, acute maternal infections

(e.g. rubella), chronic maternal infections (e.g.

syphilis, herpes), radiation, drugs (e.g. alcohol,

cocaine), maternal dysfunctions (e.g. diabetes,

hypertension).

Neonatal Precipitate birth, apnea, hypoxia (most

common), birth injury, prolonged/ difficult labor.

Postnatal Trauma, brain tumors, infections (e.g.

encephalitis, meningitis), toxins (e.g. lead,

hydrocarbons).

Manifestations

Clinical • Intellectual disability (60% of patients) • Seizure disorder (30-50% of patients) • Delayed motor development • Limb spasticity • Persistent primitive reflexes • Involuntary movements, and

ataxia(Inability to coordinate voluntary muscle movements; unsteady movements and staggering gait)

Oral Manifestations • Increased risk for dental caries and periodontal

disease • Enamel hypoplasia • Dental erosion • Delayed eruption of permanent teeth • Dilantin(Phynotoin) hyperplasia for those with

epilepsy • Increased incidence of Class II Div I

malocclusion • Increased risk for oral trauma and injury • Others: Tongue thrust, mouth breathing,

hyperactive , dysphagia, oral hypersensitivity (overreaction to touch, taste, or smell), prolonged and exaggerated bite reflexes, bruxism, sialorrhea, poor oral hygiene.

Febrile Convulsion

Are common than epilepsy Usually affects children Arises from increased body temp (>38˚C) Commonly caused by infection (non-CNS

infections) Treatment maybe bathing with tepid water

and given acetaminophen Elixir (not Aspirin) Children under 18 month should be

hospitalized because the fit may be due to meningitis

Epilepsy

Periodic disturbances in neurological function with frequent changes in consciousness.

Due to abnormal excessive electrical discharge within the brain

There is paroxysmal (sudden uncontrollable attack) electrochemical disturbance

And it is of two types clinicallyI. Petit MalII. Grand mal

Factors that precipitate epilepsy Severe stress Alcohol drinks Hypoglycemia Severe pain Administration of large doses of LA Surgical procedures

NOTE: majority of cases in epilepsy are idiopathic

Petit mal

It is of a minor character, without warning

Pt loses consciousness for a few seconds Pt seldom falls or has convulsions On lookers may not notice anything

wrong

Grand mal

Characterized by generalized convulsions

Loss of consciousness Sometimes heralded by Aura But blood pressure and pulse remain

normal Muscle contraction may affect

respiration causing cyanosis Tongue may be bitten if not protected

Clinical presentation of Epilepsy

Seizures always occur in three phases• Aura• Convulsion• Post convulsion There is a risk of airway obstruction,

vomiting and tongue falling against posterior pharyngeal wall

After seizure, pt may present with headache and doesn't recall seizures

DIAGNOSIS & INVESTIGATIONS Full history (type, onset, cause,

frequency) EEG Electroencephalograph Biochemical test: glucose & calcium

estimation Liver function test MRI scans

Dental management of Epilepsy Stress reduction protocol Administer small amount of LA Short appointments, as painless as

possible Additional anticonvulsant drugs before

procedure with consultation of pt physician

For pt with status epilepticus, treat with slow IV injection of Diazepam

ANTICONVULSANT DRUGS: USES & ADVERSE EFFECT

Drug Use Systemic adverse effect

Oral adverse effect

Carbamazepine GM Ataxia, Drowsiness Dry mouth, Erythema multiform

Valproate GM Drowsiness, Purpura, Xerostomia, stomatitis, glossitis,

Phenytoin GM Cerebella damage Gingival swelling, Xerostomia,

Ethosuximide PM Renal damage, eosinophilia

Primidone GM Drowsiness Megaloblastic anaemia

Excessive bleeding may result when combined Carbamazepine, Valproate with aspirin or NSAIDs.