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Tuesday, September 01, 2009

Sharp Brains - Cognitive Enhancement via Pharmacology AND Neuropsychology, in The New Executive Brain

Looks like an interesting book, via Sharp Brains.

Cognitive Enhancement via Pharmacology AND Neuropsychology, in The New Executive Brain

(Editor's Note: given the growing media attention to three apparently separate worlds -cognitive enhancement via drugs, brain fitness training software, computerized neurocognitive assessments-, I found it refreshing to see our co-founder Elkhonon Goldberg introduce the topic of cognotropic drugs with an integrative perspective in the much updated new edition of his classic book, now titled The New Executive Brain - By Elkhonon Goldberg The New Executive Brain: Frontal Lobes In A Complex World. Below goes an excerpt).

For many neuropsychologists, like myself, science is a labor of love, but seeing patients is bread and butter. Traditionally, the clinical contribution of neuropsychology has been mostly diagnostic, with precious little to offer patients by way of treatment. Neuropsychology is not the only clinical discipline for years consigned to helpless voyeurism. Every discipline concerned with cognition shares this humbling predicament. A psychiatrist treating a schizophrenic patient or a depressed patient finds him- or herself in a similar position. There are ample pharmacological tools to treat the patient’s psychosis or mood, but very few to treat the patient’s cognition. Even though psychiatrists increasingly recognize that cognitive impairment is often more debilitating in their patients than psychosis or mood disorder, traditionally, very little direct effort has been aimed at improving cognition.

A neurologist treating a patient recovering from the effects of head injury does not fare much better. There are adequate means to control the patient’s seizures but not his or her cognitive changes, despite the fact that cognitive impairment is usually far more debilitating than an occasional seizure. Society has been so preoccupied with saving lives, treating hallucinations, controlling seizures, and lifting depression that cognition (memory, attention, planning, problem solving) has been largely ignored. Granted, various neuroleptics, anticonvulsants, antidepressants, sedatives, and stimulants do have an effect on cognition, but it is an ancillary effect of a drug designed to treat something else.

Alzheimer’s disease and other dementias have been society’s wake-up call. Here, in the most affluent country in the most affluent of times, human minds were succumbing to decay before human bodies, a sharp challenge to the tacit popular belief that the “body is frail but soul is forever.” This provided an impetus for the development of an entirely new class of drugs, which can be termed familially as “cognotropic.” Their primary and explicit purpose is to improve cognition.

Since medical and public preoccupation with dementia focuses on memory, most of the pharmacological efforts have been directed at improving memory. At the time of this writing, a handful of drugs known as “Alzheimer’s drugs” or “memory enhancers” have been approved by the U.S. Food and Drug Administration (FDA). In reality, both designations are somewhat misleading. The drugs in question are anticholinesterases. They are designed to inhibit an enzyme necessary for the breakdown of the neurotransmitter acetylcholine in the synapse, and thus to prolong its action after its release into the synapse. Acetylcholine is a neurotransmitter that plays an important role in memory as well as in other cognitive functions. Biochemical processes involving acetylcholine (“cholinergic transmission”) are impaired in Alzheimer’s dementia, but they are also impaired in many other disorders.

My first encounter with this class of drugs took place in the late 1970s and involved physostigmine (Antilirium), a first-generation anticholinesterase, now out of use as a cognitive enhancer. We gave it to a patient recovering from severe head injury. The problem with physostigmine was that its length of action (halflife) was so miserably short that no sustained therapeutic effect could be reasonably expected. At best, a very fleeting, short-term improvement could be hoped for. To capture this improvement, my colleagues and I designed a brief battery of neuropsychological tests, which my research assistants Bob Bilder and Carl Sirio rushed to administer with clockwork timing during carefully calculated, and very narrow, windows of opportunity. Fleeting though it was (and at times overshadowed by vicious diarrhea), subtle memory improvement was reproducibly present. This was a cause for hope that with some improvements this class of medications could someday have real clinical value.

A number of years later, tacrine (Cognex) appeared on the market, followed by donepezil (Aricept). These drugs are also anticholinesterases, but with a much longer action and a more meaningful therapeutic effect. They should not be thought of as exclusively “Alzheimer’s drugs” since their utility is not limited to Alzheimer’s disease. I have observed a significant, albeit transient, therapeutic effect of these drugs on cognition in patients with Parkinson’s disease and brain damage due to hypoxia.

. . . .

Our previous interview with Dr. Goldberg:

- On Cognitive Training and Brain Fitness Computer Programs

Read the whole excerpt.


1 comment:

  1. excellent writing, with a commitment and a love for fraternity.
    I found that sending vibrations thru chanting of particular sounds, and meditation of no thots, and bringing the patients to silence, clears off their nervousness, shaky hands, and brain problems to a certain extent. Remember one thing, Oxygen when absorbed more by the body thru lungs, it rejuvenates the brain and can work wonders,
    by yoga alone.
    This way, I always think, avoiding the excessive usage of drugs esp for young children identified rightly or wrongly with ADHD or dyslexia.
    I could cure one child of 8 yrs who had a marginal dyslexia, corrected in time without much efforts but with more hardwork of 2 hrs dedication every day for 2 months - practising yoga and chanting etc
    -thanks for your good thots,
    d parameswaran
    proj director
    sunflowerdancetrust for social results
    india
    www.sunflowerdance.com

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