08 - 3. Organic disorders

3. Organic disorders

© SPMM Course 3. Organic disorders

Chapter F00 in ICD-10 discusses organic disorders such as dementia. Major categories include dementia  of  Alzheimer’s  disease,  vascular  dementia,   dementia in other diseases classified elsewhere (includes  CJD,  Parkinson’s  dementia  etc.),  organic amnesic syndromes, delirium, other mental disorders due to brain damage (includes organic hallucinosis, catatonic disorder, mild cognitive disorder etc.) and personality change due to brain damage. Depressive pseudodementia: This is not a separate diagnostic entity, but a descriptive term often used in old age psychiatry. Depression in elderly patients may present as dementia clinically. This is called depressive pseudodementia. Here the patient complain of memory impairment, difficulty in sustaining attention and concentration and reduced intellectual capacity. Major clinical features differentiating pseudo-dementia from dementia are tabulated below Pseudodementia Dementia Onset can often be dated precisely Onset can be dated only within broad limits Symptoms usually of short duration before seeking help Symptoms usually of long duration before medical help is sought Rapid progression of symptoms after onset Slow progression of symptoms throughout course Patients complain actively of the cognitive impairment Patients often complain little of their cognitive difficulties (may even conceal disability and appear unconcerned) Nocturnal accentuation of dysfunction uncommon Nocturnal accentuation of dysfunction common Attention and concentration often well preserved Attention and concentration usually faulty On  direct  testing  ‘Don'ʹt  know’  answers  are  typical  (the   patient is not trying hard) Near-miss answers are frequent in cognitive tests (the patient is trying but not efficient) Memory loss for remote events may be more severe than for recent ones Memory loss for current events usually more severe than for remote events (Adapted from Kaplan & Sadock - Synopsis of psychiatry-10th edition) Dementia  in  Alzheimer’s  disease  (diagnostic  criteria) x Global deterioration in intellectual capacity and disturbance in higher cortical functions like memory, thinking, orientation, comprehension, calculation, language, learning DSM-5 AND CATATONIA Presence of three catatonic symptoms from a total of 12 is required to diagnose catatonia. In DSM-5, catatonia may be diagnosed as a specifier for depressive, bipolar, and psychotic disorders; as a separate diagnosis in the context of another medical condition; or as another specified diagnosis.

© SPMM Course abilities and judgement, an appreciable decline in intellectual functioning and some interference with personal activities of daily living. x Insidious onset with slow deterioration x The absence of clinical evidence or findings from individual investigations suggestive of organic brain disease or other systemic abnormalities. x Absence of sudden onset or physical/neurological signs Remember 5As x Amnesia-Impaired ability to learn new information and to recall previously learned information x Aphasia-Problems with language (receptive and expressive) x Agnosia-Failure of recognition, especially people x Apraxia-Inability to carry out purposeful movements, even though, there is no sensory or motor impairment x Associated disturbance-behavioural changes, delusions, hallucinations Some patients exhibit mild cognitive impairment before the onset of full-blown dementia. A significant proportion of those with MCI does not develop dementia: if they convert to dementia, the most common dementia to develop is Alzheimer’s  dementia. Vascular dementia x Presence of a dementia syndrome, defined by cognitive decline from a previously higher level of functioning and manifested by impairment of memory and of two or more cognitive domains (orientation, attention, language, Visuospatial functions, executive functions, motor control and praxis) and deficits should be severe enough to interfere with activities of daily living not due to physical effects of stroke alone. (NINDS AIREN criteria) x Onset may usually follow a cerebrovascular event and is more acute x The course is usually stepwise, with periods of intervening stability. x Focal neurological signs & symptoms or neurological evidence of cerebrovascular disease (CVD) judged etiologically related to the disturbance. CVD defined by the presence of focal signs on neurological examination, such as hemiparesis, lower facial weakness, Babinski sign, sensory deficit, hemianopia and dysarthria and evidence of relevant CVD by brain imaging (CT or MRI) x Emotional and personality changes are typically early, followed by cognitive deficits that are often fluctuating in severity.

© SPMM Course x Symptoms are not occurring during the course of the delirium Dementia with Lewy Bodies x Spontaneous motor features of Parkinsonism x Fluctuating cognition with notable variation in attention + alertness x Recurrent visual hallucinations, which are typically well formed and detailed. x A progressive cognitive decline that is severe enough to interfere with normal social and occupational functioning and memory loss may not be an early feature, but it is usually evident with progression. x Supportive features: Neuroleptic sensitivity and history of falls Parkinson’s  disease  dementia: If the Parkinsonian symptoms have existed for more than 12 months  before  dementia  develops  then  a  diagnosis  of  Parkinson’s  disease  dementia  is given. If both motor symptoms and cognitive symptoms develop within 12 months, then it is conventional to give a diagnosis of Lewy body dementia. Frontotemporal dementia x Insidious onset and gradual progression x Early loss of personal and social awareness x Early emotional blunting, Early loss of insight x Behavioural features: Early signs of disinhibition, decline in personal hygiene & grooming, mental rigidity, inflexibility, hyperorality, stereotyped and perseverative behaviour x Speech disorder: Reduced output + signs such as stereotypy, echolalia, and perseveration x Affective symptoms: Anxiety, depression, and frequent mood changes, emotional indifference. x Physical signs: Incontinence, primitive reflexes, akinesia, rigidity and tremor. Notable features in other organic disorders x Most cases of delirium recover in 4 weeks; in chronic lung disease, subacute bacterial endocarditis and carcinoma delirium may last up to 6 months. x In organic hallucinosis, insight may be present. x Encephalitis and CO poisoning can cause organic catatonia. x Influenza can cause post-infective depression.