Organic Mental Disorders

Organic Mental Disorders DementiaProgressive, usually irreversible, global cognitive deficits.MemoryDysphasiaAgnosiaApraxiaImpaired executive functionPersonal disintegration EtiologyDegenerative Alzheimers, Parkinsons, IntracranialInfection Prion disease, neurosyphilis, HIV, EndrocrineMetabolicVitamin B12 DeficiencyToxins - alcoholClinical features

InvestigationsFBC; LFT; U&E; glucose; erythrocyte sedimentationrate (ESR); thyroid-stimulating hormone (TSH); calcium; magnesium;phosphate; Venereal Disease Research Laboratory (VDRL) test for syphilis;HIV; vitamin B12 and folate; C-reactive protein; blood culture; LP; EEG;chest X-ray (CXR); ECG; CT (optima and axial protocol); MRI; SPECT.ManagementEtiologic:cholinesterase inhibitors: tacrine, donepezil, revastigmine, metrifonateHAARTTreatment of co-morbid conditions:depression, agitation, psychosisAdjunctive treatments:vit.E, hydergine, selegeline, ginkgo biloba

Alzheimers DAT dementia of Alzheimer typeMost common cause 70%A degerative disease of the brain with prominent cognitive and behavioral impairment sufficiently severe to interfere with social and occupational functionPossible factors : Smoking, estrogen, NSAID, vit EPathophysiologyAmyloid plaquesNeurofibrillary tanglesGenetics 40% have a positive family history

Clinical featuresEarly symptoms Failing memory, changes in behavior wandering, irritability Middle symptomsAphasia, apraxia(awkwardness with the sequence of dressing), agnosia(trouble locating body parts)Late symptoms Fully dependentPhysical deterioration IncontinencePsychiatry symptomsDelusions, hallucinations, depressionBehavioral dan personality changes aggression, sexual disinhibitionAssessmentDetailed historyMSECognitive testingPhysical examinationBlood testsEEGBrain imaging

Pharmacological interventionFirst generation AChEIsTacrine SE- GI problems, hepatotoxicSecond generationDonepezil piperidine derivative, long half life, highly selectiveSE- GI, bradycardia, KI-asthmaDose 1x daily 5-10mg/dayRivastigmineShort half lifeSE- GIDose- start with 1.5mg BDGalantamine Selectively inhibit AChE4-12mg BD

NMDA receptor partial antagonisttMemantineOthers Vit E, selegilineDementia with lewy bodiesCommon form of senile dementia that shares clinical and pathological feature of Dat and parkinsons

Clinical featuresDementia, parkinsonism, fluctuating cognitive performanceComplex hallucinations-visual(60%)Transient disturbance of conciousness

Pathological features

ManagementNo compelling data indicate that medications can decreaase cognitive declineUse drugs with caution!Vascular dementiaSecond common cause after DATRisk factorshypertension, smoking, hypercholesterolemia, diabetes mellitus, and cardiovascular and cerebrovascular disease.

Management Establish causative factors. Medical or surgical diseases that are contributory need to be treatedearly. Daily aspirin may delay course of disease.General health interventions include changing diet, stopping smoking, managing hypertension, optimizing diabetic control, and increasing exercise.