Mental Retardation and Convulsions PDF

Mental retardation Definition: Handicapping disorder with the following diagnostic criteria: 1. Subnormal intelligence quotient "IQ" (less than or equal to 70% ) 2. Limitations exist in two or more of the adaptive skills e.g. communications, social skills, self care, safety, functional a...

Mental retardation Definition: Handicapping disorder with the following diagnostic criteria: 1. Subnormal intelligence quotient "IQ" (less than or equal to 70% ) 2. Limitations exist in two or more of the adaptive skills e.g. communications, social skills, self care, safety, functional academics, and work. 3. Manifest before age of 18 years (if after 18 years, it is called dementia). Etiological classification Clinical picture Delayed achievement of developmental milestones is the cardinal symptom of mental retardation. In infancy: delayed social development (delayed social smile, delayed recognition of the mother), vision and hearing impairment, and gross motor delay. In early childhood: delayed speech, delayed fine motor skills, and delayed sphincteric control. In late childhood: behavioral difficulties, school failure and learning difficulties Diagnosis Delayed developmental milestones suggest the diagnosis. Detailed history (especially obstetric and neonatal history), detailed pedigree, and thorough examination (dysmorphism, full neurologic examination and evaluation of growth and development) are required to find the cause of mental retardation. Vision and hearing testing In some cases no cause can be identified.  Investigations should be directed according to the clinical possibilities (skull x-ray, CT scan, fundus examination, karyotyping, and serological investigations). Screening tests are indicated to detect early the preventable/curable conditions e.g.: T4 and TSH (hypothyroidism). Urine reducing substance (galactosemia). Urine ferric chloride test (phenylketonuria). Some conditions may be confused with mental retardation as: cerebral palsy, blindness, deafness, and social deprivation. Prevention of mental retardation 1- Prevention of delivery of retarded children: a- Vaccination of all females against rubella before child bearing period. b- Avoidance of further pregnancies when the recurrence risk of an untreatable inherited disorders is high. c- Avoidance of conditions that may lead to acquired retardation during intrauterine, perinatal and postnatal periods. 2- Early diagnosis and treatment of preventable/treatable conditions by suitable screening tests. Management of mental retardation In treatable conditions, the specific therapy will prevent further impairment of mental abilities, e.g: Congenital hypothyroidism: requires life long therapy with thyroid hormone. Galactosemia: elimination of galactose from the diet and using galactose-free diet. Phenylketonuria: elimination of phenyl- alanine using phenylalanine-free milk and diet. In untreatable conditions management is supportive: a-Treatment of associated problems e.g. epilepsy or hearing defect. b- Education and training according to the degree of mental retardation. c- Emotional support to the family. d- Institutionalization for the profoundly retarded children. Cerebral palsy Definition: cerebral palsy is defined as a non-progressive disorder of cerebral function involving posture and movement (purely motor syndrome), resulting from disorders of early brain development, dating to events in the prenatal, natal, or neonatal period. It is often associated with epilepsy, mental retardation, squint, feeding disorders (poor suckling & swallowing), impaired hearing, impaired vision, abnormalities of speech, and microcephaly. Persistence of primitive neonatal reflexes is characteristic. Prevalence of CP has been rising in the last 40 years. It may vary between 1.5 and 3.0 per 1000 live births in developed countries and up to 5.6/1000 live birth in developing coutries. 2- In developed countries, 70% of cerebral palsy cases occur prior to birth (prenatal); 20% occurs during the perinatal period; 10% occurs during the first two years of life (postnatal). This is reversed in developing countries due to lack of proper antenatal care, poor obstetric care, consanguineous marriages and inappropriate diagnosis and treatment of postnatal infections. 3- CP is more common among boys than girls. 4- Most (77.4%) of the children identified with CP had spastic CP. Causes of cerebral palsy  Types of cerebral palsy 1- Spastic type: is the most common type. Manifestations of upper motor neuron lesion (spasticity, increased deep tendon reflexes, ankle clonus and Babinski sign) are present. Spastic hemiplegia: manifestations of UMNL are present on the affected side. The arm is often more involved than the leg. Hand preference occur at early age. Walking is delayed and circumductive gait is apparent.  Spastic diplegia: manifestations of UMNL affect the 4 limbs but lower limbs are more affected than the upper. When the child is suspended by the axillae, a scissoring posture of the lower limbs is maintained. Spastic quadriplegia: is the most severe form of cerebral palsy because of marked motor impairment of all extremities and high association with mental retardation and seizures. Speech and visual abnormalities are common. Spastic monoplegia and paraplegia: may also occur. 2- Extrapyramidal cerebral palsy (may be athetoid or atonic): it is relatively rare especially after improved prevention of kemicterus. These infants are characteristically hypotonic with poor head control. Athetoid movements may not become evident until one year of age and speech is affected. Intellect may be preserved. Feeding disorders, may be deafness. 3- Ataxic cerebral palsy: it is due to perinatal asphyxia affecting the cerebellum. It is characterized by hypotonia, intention tremors, nystagmus, stacatto speech, ataxic gait, and incoordination of voluntary movements. 4- Mixed types. Associated Deficits and Complications: Because CP is secondary to brain lesion affecting motor regions, other brain areas might be affected leading to one or more of the following manifestations: 1- Epilepsy. (Most Common) 2- Mental retardation. 3- Microcephaly. 4- Learning disorder. 5- Language disorders: As central aphasia, dyslalia and dysartheria. 6- Hearing defects: Cortical deafness or sensori-neural hearing loss. 7- Visual defects: Cortical blindness, squint, visual acuity defect. 8- Psychological disturbance: Emotional instability, autistic like features, anxiety, sleep disorder. 9- Malnutrition: Either obesity (due to ↓ activity) or failure to thrive. 10- Teething defects as decayed teeth. 11- Bowel disturbance as constipation. Reasons for failure to thrive in CP: 1- Inadequate food intake because of difficulty in chewing and swallowing. 2- Recurrent vomiting due to assocaiated gastro-esophageal reflux 3- Frequent aspiration (due to lack of palatopharyngeal coordination). 4- High basal metabolic rate as in dyskinetic CP with involuntary movements. However, failure to thrive of genetic cause (not CP) should be excluded as in cases of inborn errors of metabolism especially if there is a similar condition in the family (CP is not genetic or hereditary disease). Diagnosis Thorough history and physical examination: to eliminate progressive disorders of the CNS. CT scan and MRI: to detect degree of brain atrophy, to detect the cause e.g. brain malformations, and to rule out brain tumors or degenerative brain disease. Tests of hearing and visual function: audiometry and fundus examination. EEG: for cases with epilepsy. TORCH screen, and metabolic screen: if needed. CP prevention, there should be general improvement of prenatal, perinatal and postnatal care for all children in addition to reduction of environmental hazards. Strategies include: 1- Immunization of all females against rubella. 2- Maternal screening for toxoplasmosis early in pregnancy. 3- Prevention of prematurity. 4- Prompt prevention and treatment of eclampsia and placental insufficiency. 5- Improvement of neonatal care. 6- Prevention of kernicterus (bilirubin encephalopathy) 7- Early diagnosis and treatment of meningitis. 8- Prevention and prompt treatment of head injuries. 9- Early diagnosis and treatment of dehydration and malnutrition Treatment: Physiotherapy: prevents gross contractures. Serial plastering and splinting are required to treat positional deformity. Treat epilepsy, and reduce abnormal muscle tone: Dantrolene sodium, Baclofen, Botox A injection Surgical procedures: to improve the mobility. Speech therapy and hearing aids. Psychosocial support Care of feeding and defecation. Assist walking: walkers, standing frames, motorized wheel chair. Convulsions Definition A paroxysmal disturbance of brain function that may be manifested by involuntary motor, sensory, autonomic, behavioral disturbances, alone or in any combinations, often accompanied by impairment or loss of consciousness. Convulsions are among the most common pediatric emergencies. Causes of acute seizures in infants and children Diagnosis: The following investigations may help in diagnosis: Febrile Convulsions  Definition: febrile seizures are seizures that occur between the ages of 6 and 60 mo (peak 12-18 mo) with a temperature of 38°C or higher, that are not the result of CNS infection or any metabolic imbalance, and that occur in the absence of a history of prior afebrile seizures. Incidence: between 2% and 5% of neurologically healthy infants and children experience at least one, usually simple, febrile seizure.  A simple febrile seizure is a primary generalized, usually tonic- clonic, attack associated with fever, lasting for a maximum of 15 min, and not recurrent within a 24-hr period. Most patients have a very short postictal state and usually return to their baseline normal behavior and consciousness within minutes of the seizure. A complex febrile seizure is more prolonged (>15 min), and/or is focal, and/or recurs within 24 hr.  Febrile status epilepticus is a febrile seizure lasting longer than 30 min. There are no clinical features suggesting CNS infection, meningeal irritation, or increased intracranial pressure. Evidence of extracranial infection (e.g. tonsillitis, pharyngitis, otitis media, roseola) Differential diagnosis 1- From other causes of convulsion with fever: meningitis, encephalitis, or brain abscess. 2- From epileptic fit precipitated by associated fever. Investigations Usually not needed in children with simple febrile convulsions. For complex cases: a) Lumbar puncture and CSF analysis: to exclude CNS infections. b) Neuro imaging (CT, MRI). c) Blood glucose, serum electrolyte, toxicology screen and EEG. Management of febrile convulsions Parents should be reassured, and educated on how to handle a seizure acutely. Careful search for, and treatment of the cause of fever. Active measures to control the fever including the use of antipyretics, and water bath. Because iron deficiency anemia increases risk of febrile convulsions, iron therapy is given to these cases.  If the seizure lasts for longer than 5 min, acute treatment with rectal diazepam, or buccal or intranasal midazolam may be used. In cases of frequently recurring febrile seizures, intermittent oral clonazepam (0.01 mg/kg every 8-12 hr up to a maximum dose of 1.5 mg/day) or oral diazepam (0.33 mg/kg every 8 hr) can be given during febrile illnesses. Antiepileptic therapy, is not recommended for children with one or more simple febrile seizures. Prognosis of febrile convulsions Febrile convulsions rarely develop into epilepsy, and usually they spontaneously disappear without specific therapy. The risk factors for development of epilepsy in children as a complication of febrile convulsions include (EEG is indicated): a- Positive family history of epilepsy. b- Initial febrile seizure prior to 9 mo of age. c-Prolonged or atypical febrile seizure. d- Frequent seizures. e- Motor or mental deficits. Common anticonvulsant drugs Treatment of acute convulsions : Diazepam: It is used as an emergency treatment for acute seizures and for prophylaxis against febrile convulsions. Dosage is 0.2 to 0.3 mg/kg/dose I.V; observe respiration because it may cause respiratory depression Phenytoin: is used in treatment of status epilepticus by 1.V drip. Phenobarbital: phenobarbital treats tonic-clonic and simple partial seizures in newborn infants. Epilepsy Definition: two or more unprovoked seizures that occur at interval greater than 24 hours (i.e recurrent seizures). It is the main cause of recurrent convulsions. Causes 1. Idiopathic (primary) in 80% of cases 2. Organic (secondary) in 20% of cases Congenital cerebral malformation. Degenerative brain diseases. Post-traumatic, post-hemorrhagic. Post-infection. Post-toxic, post-anoxic Some inborn errors of metabolism In focal seizures: the first clinical and EEG changes suggest initial activation of a system of neurons limited to part of one cerebral hemisphere. In generalized seizures, the first clinical and EEG changes indicate synchronous involvement of all of both hemispheres.  Focal seizures can be described as motor or non-motor seizures and are further characterized by preserved or impaired awareness (or consciousness). Focal aware seizure (previously: simple partial seizure): a focal seizure with no alteration in consciousness. Focal seizures with impaired awareness: (previously: complex partial seizure): focal seizures with altered awareness of the surroundings. Investigation 1. EEG. 2. Metabolic screen: serum Na, Ca, Mg, glucose 3. CSF examination in suspected CNS infections. 4. CT brain in focal lesions, increased intra cranial pressure, and in cases resistant to treatment. 5. Serum anticonvulsant level to confirm therapeutic range, and if suspected drug toxicity Treatment of epilepsy 1. Advise the parent: to watch the child during swimming, passing traffic, and never to stop the antiepleptic drug suddenly. 2. Anti-eplieptlc drugs: - Only one drug is used with small dose - If no response: gradually increase the dose. - In resistant cases a 2nd drug can be used alone or in combination. - Duration of therapy is at 1east 2 years after 1ast attack. Dosage and main side effects of some antiepileptic drugs CSF Findings in health and disease WITH MY BEST WISHES The most common type of C.P is a. Spastic b. Extrapyramidal c. Ataxic d. Mixed type One of the following is not true regarding spastic hemiplegia: a.Manifestations of UMNL are present on the affected side. b.Kernicterus is a major risk factor c.The arm is often more involved than the leg d.Walking is delayed e.Circumductive gait is apparent