Psychiatry for Physicians – Dementia – Other Types

Other categories of dementia worth mentioning are dementia due to Pick's disease, dementia due to Creutzfeldt-Jakob disease, dementia due to Huntington's disease, dementia due to Parkinson's disease, dementia due to HIV disease, substance induced dementia, and dementia syndrome of depression.

Dementia due to Pick's disease is a variety of frontotemporal dementia. In it there is progressive reduction of speech, loss of insight and stereotyped, perseverative behaviors, together with reliably late onset of memory and visuospatial disturbance. SPECT and PET are the two most useful imaging technique for diagnosis it.

The infectious agent for Creutzfeldt-Jakob disease is the Piron. Clinical deterioration is very rapid in this dementia. Progressive decline with death within one year is common for this problem. Intellectual destruction, myoclonic jerks, muscle rigidity, and ataxia are some features of this illness. EEG, functional imaging and biopsy are some useful techniques for this illness.

Dementia in Huntington's disease occurs due to some idiopathic, inherited, autosomal dominant neurodegeneration. It starts after 40 years of age and deteriorates to the extreme in around 17 years course. Irritability, apathy, depression, mania, defective cognition, memory retrieval deficiency etc. are common features. Absence of aphasia helps to differentiate it from DAT. CT or MRI can be useful for the diagnosis of this dementia.

Prevalence of dementia amongst Parkinson's Disease patients is about 25%. It is noted especially among late patients. Presentation of dementia in PD is complicated that primarily representations degeneration of subcortical ascending system with neuronal loses in multiple neurotransmitter related systems.

HIV type 1 causes dementia. It causes atrophy and demyelination of subcortical white matter. Three subtypes are seen among HIV type 1 seropositive patients. They are subcortical, cortical and non-affected varied according to the neuropsychiatric impact. Substance induced dementia is mainly seen in persons with alcohol abuse.

Depression can cause dementia syndrome that is called pseudodementia. But dementia and depression can occur due to the same underlining pathology. Other causes of dementia include mainly the structural damage to the brain in different situations. But causes like brain tumor, vitamin B 12 deficiency are also there in the affected causes.