Cerebral palsy is the medical term covering a whole group of neurological conditions. These conditions vary one from another as the clinical features of spasticity, athetosis, ataxia, tremor, rigidity or atony predominate, but having one feature in common - a disorder of motor control. All forms of cerebral palsy result from injury to or developmental anomaly or disease of the brain, which usually arises before or during, but sometimes after, birth. These disorders of motor control may be further complicated by associated mental, visual, auditory and speech defects, by emotional instability and by epilepsy. The physical handicap in any particular case may range from slight lack of control in one limb to complete physical helplessness. The physical disabilities, though usually the most obvious, are not necessarily the only, or even the most serious, problem. Any degree of mental ability or disability may be associated with any degree of physical handicap; conversely, severe physical disability does not necessarily indicate severe mental disability.