Neurological Disorders – Definitions, Prevalence, Categories, and Etiology

By Jodie, Kelsey, Christianne, and Tanya

 

As per Winzer (2008)

 

Neurological Impairments are damages or dysfunctions of the brain and/or spinal cord. Such damage could occur before, during, or after birth.

 

Prevalence of Neurological Disabilities

Cerebral Palsy – Cerebral Palsy is also referred to as “Little’s Disease” after the 19th century surgeon who described it.  It is a significant developmental motor disability caused by damage to the brain before, during, or after birth. Cerebral Palsy is the most common crippling condition in children. 

Most incidence rates put it at 1.5 to 2 cases per 1,000 live births, 50,000 Canadians have it. It is more common in boys than in girls. Two thirds of cases are present at birth. As well 25% of cases have no definable cause, but the most likely factors are cognitive disability of Mother, premature birth, low birth rate, and delay of 5 minutes or more before baby’s first cry.

Spina Bifida – Spina Bifida is a congenital midline defect of the spinal column Midline defects are“clefts” as a result from failure of parts of the embryo to fuse completely. Technically, the term Spina Bifida refers to a defect in the bony arch of the vertebrae protecting the spinal cord. When the bony arches don’t fuse together, it leaves part of the nerve fibres of the spinal cord exposed.

Worldwide, it occurs every 0.1 to 4.13 live births per every 1,000. In Canada, the highest rates are in Newfoundland and Labrador. It has a slight tendency to run in families and when one baby is born with it, there is a 4 – 5% chance of the siblings being born with it too.

Hydrocephalus – Hydrocephalus is a condition characterized by an excessive accumulation of cerebrospinal fluid in the brain due to an obstruction of its flow. A blockage of flow results in the accumulation of cerebrospinal fluid in an enclosed area, placing pressure on the brain and the skull. This pressure creates thinning of bone and separation of sutures (seams between plates of the skull). The fluid also presses on brain tissue, causing distortion of brain substance and damage/death to neurons.

Epilepsy – Epilepsy is a condition produced by a sudden violent electrical discharge of brain cells. This results in an almost instantaneous disturbance of sensation, loss of consciousness, convulsive movements (seizures) or a combination of all of these disturbances. The most commons causes of Epilepsy are brain tumors or stroke, head trauma, injuries, infections or systemic illness of Mother during pregnancy, brain injury to infant during delivery, aftermath of an infection or poisoning from substance/drug abuse. In 75% of cases, a specific cause cannot be found.

More than 1% of the population is affected, with over 280,000 of them being Canadians. As well 70% - 80% of cases develop before age five. One in every 2,000 children are diagnosed with Epilepsy yearly, which equals 14,000 new cases annually.

Tourette syndrome – Tourette syndrome is a condition characterized by multiple involuntary muscular, cerebral and sometimes vocal tics that occur many times a day, usually in bouts. Age of onset is usually between ages 2 – 15, with 6 – 7 year olds the most common. Tourette syndrome results from a chemical imbalance in the brain, but the exact neurological glitch is unknown.

Around 1.6% of the entire population is affected with Tourette syndrome. About 3 times as many males are affected than females. About 50% of those affected show signs of hyperactivity, short attention spans, restlessness and impulse control. About 30% - 50% have caprolia, the verbal tic that results in an uncontrollable uttering of obscenities.

Head Trauma – Among adolescents today, vehicle accidents involving passenger vehicles such as automobiles, motorcycles and bicycles are the most common cause of head trauma. TBI (traumatic brain injury) is almost as frequent in children under the age of 15. Among young children, head injuries result from falls, bikes, other recreational activities or assaults/abuse.

TBI is defined as an insult to the brain, not of a degenerative or congenital nature, but caused by an external physical force that may produce diminished or altered state of consciousness, which results in an impairment of cognitive abilities of physical functioning.

In the USA, one million people per year are diagnosed with TBI. Injuries, usually accidental, are the leading cause of death for children aged 1 – 14; almost half of these deaths occur in children aged 1 – 4. Boys are involved twice as often as girls. More than 300 children die and more than 20,500 are hospitalized with serious injuries.

Drug Exposed Children – It is difficult to attribute specific characteristics to certain drugs because abuse of multiple drugs is so common. Caregiving is vital in mitigating or exacerbating pre-natal exposure effects. Prenatal exposure is usually combined with other risk factors (poverty, neglect, drug abuse by others in the home). Mothers may be passive, lacking emotional involvement and more prone to abuse their children.

Fetal Alcohol Spectrum Disorders (FASD) – FASD is an entire spectrum of disorders that include such diagnostic categories as neurobehavioural disorders, statis encephalopathy and Fetal Alcohol Syndrome (FAS). As one of the disorders in the spectrum, FAS is a clinical diagnosis.

Because prevalence rates of FAS in the past have relied on different criteria, they tend to be quite scattered. With a more settled process, we can expect more clear prevalence rates to emerge. At the moment, the incidence in the general population is estimated at about 1.9 per every 1,000 live births. About 1 in every 750 infants is born with FAS.

 

Categories

Cerebral Palsy

Cerebral Palsy can be classified by topographical (referring to parts of the body) or by type.

Topographical:

•           Monoplegia is when one limb impaired

•           Diplegia is when four limbs are involved, with the legs most impaired

•           Hemiplegia is when one side of the body is impaired

•           Paraplegia is the lower limbs of the body are impaired

•           Triplegia is when three limbs impaired

•           Double Hemiplegia is when both sides of the body are impaired, with each side affected differently

•           Quadriplegia is when all four limbs are impaired

Type:

•           Spastic or Pyramidal cerebral palsy has suffered damage to the motor cortex or to the pyramidal tracts of the brain.  This results in problems with voluntary movements, which means that children with this type of cerebral palsy cannot move when, and how they choose. This affects 50% of children with cerebral palsy.

•           Extrapyramidal is characterized by constant, involuntary writhing movements.  Children show difficulty in maintaining posture and are unable to stop moving when they want to.  This affects 25% of children with cerebral palsy.

•           Ataxic is poor coordination of the movements associated with balance, posture, and spatial orientation.  Children walk with a wide gait and lack coordination of both fine and gross motor movements.  Eyes are often uncoordinated.  This affects 15% of children with cerebral palsy. 

•           Mixed Cerebral Palsy is when a child shows mixed effects like spasticity of the legs and rigidity of the arms.  This affects approximately 25%.

 

Spina Bifida

There are two types of Spina Bifida:

·         Spina Bifida Occulta is the mildest form of the condition and has few or no negative effects.  The only visible sign of the condition, if any, is a clump of hair on the skin covering the area of the cleft.  Of the affected population 40% have this type.

·         Spina Bifida Cystica with meningocele is when the membranes surrounding the spinal cord protrude from the plane of the spine and form a sac containing cerebrospinal fluid.  Surgery is usually performed in the first days of life to restore the sac within the spinal column.  Following surgery there usually is no more difficulties.  This type affect 4%.

Spina Bifidia with myelomeningocele is the most severe type and results in a protruding sac that contains parts of the spinal cord as well as cerebrospinal fluid.  Surgical treatment is necessary to deal with the sac, but the neurological damage is irreversible.  This type affects 96%.

Hydrocephalus

Hydrocephalus is an excessive accumulation in the brain of cerebrospinal fluid due to an obstruction in flow.  This causes pressure on the brain and skull and can result in a range of disorders such as mental retardation, motor disorders, seizures, and even death.

Epilepsy

Generalized Seizures are often accompanied by loss of consciousness and most have motor components.  They include absence seizures (petit mal), myoclonic seizures, tonic-clonic seizures (grand mal) and atonic seizures. 

Tonic-clonic seizures-child loses consciousness, falls, and develops generalized stiffness of the body.  The person may lose bladder and bowel control, bite the tongue, and froth at the mouth.  Usually after 2-5 minutes the person regains consciousness and may experience confusion, headache and then a period of deep sleep.

Absence seizures-an extremely brief loss of consciousness and is most frequently seen in children.  Seizure lasts 15 to 30 seconds, the child will stare vacantly and during this period there is a loss or clouding of consciousness.  

Partial Seizures-altered consciousness, change of body position or limbs, confused activity, a dazed expression, nausea, vomiting, drooling, mumbling, wandering, incoherent speech and inappropriate emotional disturbances.

Unclassified Seizures-includes all other types.

Tourette Syndrome

May show hyperactivity, short attention spans, restlessness, and poor impulse control.  Only about 30 to 50% have caprolia, which is the verbal tic that results in uncontrollable uttering of obscenities.

Head Trauma

Is not degenerative or congenital but rather caused by an external physical force. It may impair cognitive abilities or physical functioning and it can also result in the disturbance of behaviour or emotional functioning. 

Drug Exposed Children

Children who do suffer effects will have problems in class participation, the instructions, interactions, and the noises in the classroom as well the environmental noises.  Some children withdraw and others may become wild and difficult to handle.

 

Etiology

Neurological impairments result from damage to, or dysfunction of the brain and or spinal cord that may occur pre-, or postnatal. The consequences of injury vary greatly. Damage to the motor cells of the spinal cord causes flaccid paralysis. Brain injuries may result in limited specific disorders or generalized problems.

Neurological disorders include a wide range of conditions. However, they are low- incidence conditions.

Cerebral Palsy:  caused by damage to the brain, is characterized by motor disorder and is often accompanied by other disabilities. Cerebral palsy is not contagious, progressive, or curable.

Spina Bifida:  midline defects result from a failure of halves of the embryo to completely fuse. These defects or clefts may occur as cleft lip, cleft lip and palate and in other parts of the body.

Epilepsy:   is not a disease but a symptom of a disorder of the brain. However, not all brain injured individuals will be epileptic and not all epileptics will be brain damaged. When evidence of the brain damage is apparent the condition is known as symptomatic epilepsy. Idiopathic epilepsy refers to a condition of unknown origin.

Tourette syndrome:   is a condition characterized by multiple, involuntary muscular cerebral tics that wax and wanes, remit and change.

Head trauma: encompasses accidents and injuries and are the leading cause of death among Canadian children. Many affected children will require special education for a short or long period.

Drug exposed children:   exposed to drugs prenatally and suffer adverse effects that include learning disorders and problem dealing with incoming stimuli. There is however a continuum of casualty risk; problems are moderated or exacerbated by social factors such as poverty and neglect.

 

Winzer, M. (2008). Children with exceptionalities in Canadian classrooms (8th ed.). Toronto,

           

Canada: Pearson Prentice Hall, pp. 423-456