Organic Disorders2

Organic Disorders2

Dementia
Dementia is an acquired global impairment of intellect, memory and personality , but without impairment of consciousness.
It is usually but not always progressive
Although dementia is global or generalized disorder, it often begins with focal cognitive or behavioral disturbances
Most common causes: Alzheimer’s disease(50-60%), vascular dementia (20-25%), and dementia with Lewy bodies (15-20%)

Dementia

Both DSM-IV and ICD-10 definitions require impairment in two or more cognitive domains (memory, language, abstract thinking and judgment , praxis, visuoperceptual skills, personality , and social conduct) sufficient to interfere with social or occupational functioning.
Deficits may initially be too mild or circumscribed to fulfill this definition.
The fluctuation in alertness which characterize delirium is usually absent , except in dementia with Lewy bodies.

Causes of dementia

• Primary neurodegenerative disorders: Alzheimer’s, Lewy bodies, Pick’s, Parkinson’s, Prion diseses, Huntington’s disease.
• Vascular: vascular dementia, multiple strokes, focal thalamic and basal ganglia strokes, subdural hematoma
• Inflammatory and autoimmune: SLE, Bahcet’s, MS, neurosarcoidosis
• Traumatic : head injury
• Infections and related conditions: HIV, neurosyphilis
• Metabolic and endocrine : uremia, dialysis, hypothyroidism, hypoglycemia, hypopituitarism, Cushing’s disease


Causes of dementia
• 7. Neoplastic
• 8. Post-radiation
• 9. Post- anoxic
• 10. Vitamin and other nutritional deficiencies : B12, folate
• 11. Toxic: alcohol , heavy metals, organic solvents
• 12. Other causes: normal pressure hydrocephalus

Clinical features

The presenting complaint is usually of poor memory
Other features include disturbances of behavior, language , personality, mood ,or perception
Dementia is often exposed by a change in social circumstances or an intercurrent illness; indeed,patients with dementia are specially susceptible for superimposed delirium.

Forgetfulness is usually early and prominent

Impaired attention and concentration are common and non-specific features
Difficulty in new learning is usually the most conspicuous feature.
Memory loss is more evident for recent than for more remote material
Loss is more in episodic memory (day-day events) while there is relative preservation of procedural memory
Loss of flexibility and adaptability for new situations with the appearance of rigid and stereotyped routines

As dementia progress patients became unable to care for themselves and they neglect social conventions.
Disorientation for time and later for place and person is common
Behavior become aimless
Thinking slows and become impoverished in content and perseverative
False ideas often with persecutory kind appear and in later stages the thinking becomes grossly fragmented and incoherent
Eventually patient may become mute
Behavioral , affective, and psychotic features accompany the cognitive deficits during dementia.
Mortality is increased with death often following bronchopneumonia and a terminal coma


Subcortical and cortical dementia

subcortical

cortical
memory
moderate
Severe , early
language
normal
Dysphasias , early
personality
Apathetic, inert
indifferent
mood
Flat, depressed
normal
coordination
impaired
normal
Cognitive and motor speed
slowed
normal
Abnormal movements
Common, choreiform or tremor
rare


Investigations
In all patients: full blood count, ESR, urea and electrolytes, liver function tests, calcium and phosphate, thyroid function tests, syphilis serology, urinalysis, B12 and folate.
Worth considering: HIV status, chest radiograph , EEG, CT & MRI of brain, ECG, neuropsychological assessment

Treatment of dementia

• A-Drug therapy for cognitive deficits:
• Cholinesterase inhibitors: can decrease the cognitive defects in 60%of patients like tacrine( risk of liver damage is high) which lead to incompliance ,and donepezil( aricept) which has less severe side effects.
• Vitamin E :which can decrease the rate of functional decline.
• Selegiline:MAO B inhibitor which delays cognitive deterioration . Its major defect is orthostatic hypotension .No need for dietary restriction.

Treatment of dementia

• B – Drug therapy for psychosis and agitation : antipsychotic drugs like risperidone and clozapine. Also benzodiazepines like lorazepam for sleep disorders.
• Anticonvulsant agents, antiandrogens( medroxyprogesterone) for disinhibited sexual behavior.
• C -antidepressants

Epilepsy

Epilepsy is the tendency to recurrent seizures
A seizure is consisting of a paroxysmal electrical discharge in the brain and its clinical sequelae.
The tendency to recurrent seizures in epilepsy should be distinguished from isolated seizures due to : drugs, hypoglycemia, and intercurrent illness.

Psychiatric problems of epilepsy

Psychiatric co-morbidity is common in people with epilepsy, with overall rates increased at least two folds.
Many different types of psychiatric disorders are associated with epilepsy ,including cognitive ,affective ,emotional and behavioral disturbances.
These can occur before, during ,after ,and in between seizures.
The relationship between epilepsy and psychiatric disorders can be reflected in : a shared etiology (temporal lobe pathology can cause both epilepsy and psychosis), the effects of stigma, and the side effects of antiepileptic drugs that might cause psychiatric problems.


Pre-ictal psychiatric disturbances
Called prodromal states
Mood disturbances
Increasing tension , irritability
Anxiety and depression
Usually occur several hours or even days before a seizure ,and usually increasing in severity as the seizure approaches.

Ictal psychiatric disturbances

In complex partial seizures there might be affective disturbances, hallucinations, anxiety ,automatism
Absence seizures : altered awareness and automatism

Post- ictal disturbances

Impaired consciousness
Delirium
Psychosis

Inter-ictal disorders

Not related to the occurrence of fits
Cognitive problems
Psychosis
Sexual problems
Depression
Suicide and deliberate self harm
Personality change


Head injury
There are two main groups of patients who have suffered head injury:
• The relatively small group with persistent serious cognitive and behavioral sequele
• A larger group with emotional symptoms and personality change

Acute psychological effects

Occur after recovery from coma
Delirium
Delusional misidentification
Agitation and disinhibition
Inappropriate sexual behavior

Chronic psychological effects

Post-concussional syndrome: a group of symptoms include anxiety, depression and irritability, accompanied by headache, dizziness, fatigue , poor concentration, and insomnia. It might be psychologically based and usually resolve spontaneously.
Lasting cognitive impairment: deficits in memory and executive functions ( planning, problem solving, organizing, etc…)
Personality change: irritability , apathy, loss of spontaneity and drive, disinhibition, and decreased control of aggressive impulses.
Emotional disorder: depression , anxiety, and emotional lability.
Psychosis: may be transient or chronic
Boxing and head injury: 10-20% of professional boxers develop what is called punch drunk syndrome or dementia pugilistica.