Advancements in Management of Dementia

Dementia is a progressive impairment of cognitive function that eventually becomes severe enough to interfere with social behaviour and with the patient’s work. It affects memory, language expression, learning, spatial constructive abilities behaviour and thinking to varying degrees. Some 1% of persons aged 60-64, but 30% of those over 85, suffer from dementia. The age- specific  prevalence of dementia roughly doubles every 5 years after age 60. Persons with large fund of knowledge and varied interests are less likely to become demented in old age¹.

The psychopathological and neurological deficits include memory impairment (mostly recent memory ), personality change, impairment of abstract thinking and judgement, apraxia, and agnosia.

Diagnosis of dementia is based on a thorough case history, including interview of persons close to the patient,  neuropsychological examination and  Mini-mental status examination (MMSE) ¹.

Causes of dementia include degenerative diseases of the brain ( Alzheimer’s disease is the commonest), Cerebrovascular disease ( Multi- infact dementia), infectious diseases ( AIDS-Dementia complex, Prion diseases like CJD ), Metabolic diseases like Wilson’s disease), Neoplasia  ( such as  as brain tumors), Epilepsy, deficiency states ( Vitamin B12 deficiency), toxic conditions ( heavy metal poisoning), mental illnesses ( severe depression), hydrocephalus, Demyelinating disease ( Multiple Sclerosis). So, the ancillary tests for evaluation of a patient with dementia may include:  CT scan or MRI of the brain, ESR, CRP, CBC, PBS, Na, K, Ca, BUN, Glucose, Serum electrophoresis, Hepatic enzymes, HIV, Syphilis serology, TSH, Vitamin B12, folic acid, EEG, ECG, Lumbar Puncture , SPECT or PET, Antibodies ( like ANA, anti-dsDNA,etc), heavy metals tests, ammonia , cortisol, Lyme, herpes simplex serology, genetic analysis¹.

The social and economic impact of dementia  is enormous  and  its consequences on the caregivers is equally troublesome. Moreover, the treatment of memory and cognition deficts  due to varied pathologies is challenging for the physicians.  But, now we stand on the threshold of a new age in dementia care ².

Prospect of pharmacotherapy and surgical treatment of dementia is bright. The clinical trials on the beneficial effects of drugs  have provided some hope  to the patients with Alzheimer’s disease. Physical training  and cognitive support are also needed to achieve functional improvement. Studies have shown that physical activity stimulates angiogenesis, synaptogenesis and neurogenesis. Physical activity prevents dementia and conversion from mild cognitive impairment ( MCI) to dementia. A balanced diet and healthy foods predominantly vegetables, unsaturated fatty acids , grains and fish  lower risk of dementia. Keeping weight within normal limts should be encouraged. The consumption of high doses of alcohol must be avoided. The use of antihypertensive can reduce the risk of cognitive decline and dementia. Stopping smoking should be recommended at any stage of life.

Although current data is lacking to justify the use of  drugs  in prevention and treatment of various subtypes of dementia.  However, the robust clinical trials and research in this field have offered some hope to the patients suffering from dementia. A reduction in acetylcholine and choline acetyltransferase occurs in dementia type consequently impairing cholinergic pathways. Ginkgo biloba, Nicergoline, Vipocetine, Co-dergocrine mesylate ( Hydergine) and other ergoloid mesylates, Piracetam, Pentoxiphyllne , Citicholine , Cerebrolysin, Cholinesterase inhibitors ( Rivastigmine, Donepezil),  glutamate receptor antagonists ( Memantine) Galantamine, Calcium channel blocker ( Nimodipine, Nicardipine) are few therapeutic agents  which can be believed to be beneficial for preventing and treating dementia on theretical grounds.

Carotid revascularization in patients with symptomatic carotid stenosis reduces risk of stroke recurrence . The carotid revascularization can be done either by surgical approach, carotid endarterectomy  (CEA) or endovascular by carotid artery stenting (CAS). Cognitive domains include memory, executive function and language³.

Deep brain stimulation ( DBS) is a therapeutically effective neurosurgical method  for treating dementia. DBS of the fornix  and nucleus basalis of Meynert  can influence activity in the pathologic neural circuits that underlie  Alzheimer’s disease ( AD) and  Parkinson disease dementia ^4,5.

Some of the causes of dementia are amenable to cure. Virtually any metabolic or endocrine derangement can cause cognitive problems. Neurosyphilis, AIDS,,Whipple disease,, vitamin B12  , folate and thiamine deficiency, and hypothyroidism,.

Neurosurgical patients  with Brain tumor, chronic subdural hematoma and normal pressure hydrocephalus ( NPH) may present with dementia. Normal pressure hydrocephalus produces a clinical triad of  progressive dementia , urinary incontinence and gait disturbance.The dementia is of subcortical type, with marked cognitive slowing, in the absence of focal cortical deficits. Chronic subdural hematoma ( SDH) patients may also present with dementia and bur hole evacuation of hematoma is the treatment of choice. Frontal  lobe tumors like meningioma  can be excised and patient is revieved of the symptoms of memory deficits. Similarly, a CSF diversion procedure in patients of NPH can treat dementia.
In Normal pressure hydrocephalus, MRI of the brain may show features of cerebral atrophy like shrunken brain with prominent sulci and gyri and so there will be enlargement of the ventricles. But, the ventriculomegaly will be disproportionately larger when compared with the extent of cerebral atrophy. Moreover, there will be some transependymal cerebrospinal fluid transudation in the form of periventricular high signal on T2-weighted images and FLAIR images. Consequtive three day CSF tapping by Lumbar puncture with removal of about 30 ml CSF each day leads to improvement in patients of NPH and is a good indication to do a CSF diversion procedure like low pressure ventriculoeritoneal shunt surgery or Lumbperitoneal shnt surgery.

Access to the supportive care for physical , emotional and social needs of dementia patients should be the priority of the health care institutions.  Occupational therapist, Physiotherapist, Speech therapist , Neurosychologists, Medical anthropologist , Psychiatrist, Neurologist and Neurosurgeon are important components of multidisciplinary management, care and neuropsychological rehabilitation of the patient with dementa. These intervention will help the patient and their caregivers for coping with problems associated with dementia.

References:

1.     Neurology ( Thieme flexibook on clinical sciences), By  Mark Mumenthaler, Heinrich Mattle with Ethan Taub, Thieme, 4^th ed. New York. 

2.      Editorial : Azheimer’s disease: a treatment in sight? Jornal of Neurology, Neurosurgery and Psychiatry, Dr  Simon Lovestone, Robert Howard.  1995:59:66-567

3.      Treatment of vascular dementia . Brucki SMD, et al. Dementia Neuropsychol  2011 December; 5(4):275-287

4.      Stimulate or degenerate: Deep brain stimulation of the Nucleus basalis of Meynert in Alzheimer’s dementia. Laxton AW, Lozano AMD.  World Neurosurg, 2012

5.      Neurosurgical treatment of dementia: A review,  Hardenacke K, et al. World Neurosurg, June, 2012.

6.      Dementia : Differentiation and Rehabilitation Strategies By Carole Lewis and Susan Staples.