Evaluating Dementia: Assessment for Treatable Causes

"Dementia" means an acquired, persisting decrease inhematomas are two other space-occupying
mental functioning. Dementia is not a disease or aabnormalities that crowd the brain. These are masses
final diagnosis; instead, it refers to a category ofof clotted blood usually caused by traumatic blows to
symptoms that can be the result of a diverse groupthe head. The injuries producing the bleeding are not
of conditions and diseases.Everyone with eyes and aalways remembered or, if remembered, might have
brain of their own knows that dementia is a verybeen dismissed as trivial at the time they occurred.
common and serious problem, robbing some peopleThese, too, can be totally removed by a
of their memories, ability to function independentlyneurosurgeon.Normal pressure hydrocephalus is
and even their personalities. As a community-basedanother cause of dementia responding to
neurologist, I see all too many cases of dementia,neurosurgery, but in this condition the surgeon
but the part that worries me the most is whendoesn't remove a mass-lesion. Instead, the surgeon
patients, family members and even medical personnelplaces a tube inside one of the brain's swollen
assume that nothing can be done and don't evenfluid-chambers known as ventricles, allowing the
bother to evaluate for underlying causes.Although it isexcessive fluid-accumulation to drain away through
certainly true that modern medicine lacks effectivethe tube and into another body-space where it
treatments for many causes of dementia, it's alsocauses no harm. Normal pressure hydrocephalus can
true that still others can be cured or favorablybe identified not only by its dementia and enlarged
modified. It would be a shame to assume that a caseventricles, but by the concurrent presence of a
was untreatable and thereby miss something thatprominent walking impairment as well as urinary
could have been cured or better managed.So how doincontinence.Non-surgical treatments can be helpful for
dementia specialists or other doctors investigateother causes of dementia. Two conditions involving a
cases of dementia? The medical detective-workdeficiency or shortage of a biochemical are
begins with a thorough history and physicalhypothyroidism and vitamin B12 deficiency. Finding
examination.Clues might come from the history ofone of these is a blessing in disguise because they
the patient's other medical problems, the medicationare easily fixed. In hypothyroidism, the thyroid gland
list, use of alcohol or other drugs, or from otherin the neck secretes too little thyroid hormone. This is
physical problems that developed concurrently withmanaged by making up for the shortfall in pill form. In
the dementia. Apart from the general physical exam,vitamin B12 deficiency, the problem is that this
the doctor also explores the patient's ability to payessential vitamin is not properly absorbed into the
attention, remember, calculate, draw pictures, reason,bloodstream via the gastrointestinal tract, so the
comprehend words and express himself or herself.deficiency is treated by periodic injections of vitamin
Further neurological examination assesses otherB12.As people get older and acquire more medical
aspects of brain function like vision, hearing, strength,problems, their list of medications often grows longer.
coordination, sensation, walking and reflexes.AfterOne or more of the medications they take might
compiling the results of the history and examination,interfere with mental functioning. Common offenders
the physician can usually judge the relative likelihoodsare medications for urinary incontinence, anxiety or
of different underlying causes for the dementia, butinsomnia. If a problem-medication is eliminated or
follows up these clinical judgments with additionalreplaced with another drug, the patient's mental
medical tests to nail down the most likely cause. Theprowess can improve.Depression is a common cause
irreducible minimum of additional testing includes aof dementia in which the mood disorder itself
brain scan--either a CT or an MRI--plus a panel ofinterferes with concentration, memory and other
blood tests.The brain scan might detect a brainmental performance. In many cases the mental
tumor, previously unsuspected strokes, clotted bloodimpairments are more prominent than the mood
compressing the brain or hydrocephalus (water ondisturbance, causing it to be overlooked. Depression is
the brain) all of which can cause dementia and whichtreated with medication, psychotherapy, or
can also be treated. The blood tests look forboth.Chronic infections with the Lyme and syphilis
salt-and-water imbalances, abnormal blood-sugarbacteria can be resolved with appropriate antibiotics.
levels, kidney impairment, liver impairment, excessiveOccasionally a fungal infection is to blame, and can
calcium levels, thyroid disease, and deficiencies ofalso be treated with specific medication. Treatments
vitamin B12 and folic acid. Each of these problems, iffor HIV are less good, but this disease still needs to
found, would warrant specific treatment.Other testsbe identified in order to obtain the best possible
can be applied depending on the physician's judgmentoutcome.Chronic alcohol abuse can damage the brain
of their usefulness in individual cases. These mightand cause dementia. In most cases the previously
include an electroencephalogram (brain-wave test),caused damage cannot be undone, but further
lumbar puncture (spinal tap) or a PET (positrondamage can be prevented through treatment of the
emission tomographic) scan, which is a neweralcoholism. Wernicke's encephalopathy is an
technique that shows the relative activity of brainalcohol-associated cause of confusion for which
cells in different parts of the brain. Additionalinjections of thiamine (vitamin B1) are urgently
blood-tests can screen for infections with humanneeded.Strokes can also produce dementia. Strokes
immunodeficiency virus (HIV) or the bacteriaare caused by disrupted circulation which damages
associated with Lyme disease or syphilis.After all isparts of the brain. In most cases, the patient and
said and done, what turns up? Unfortunately, aboutfamily were aware of strokes when they occurred,
half the dementia cases evaluated in this way lead tobut in other cases one or more strokes might have
a diagnosis of Alzheimer's disease or similargone undetected at the time they occurred. Prior
degenerative brain disease for which there is no cure.strokes cannot be undone, but recognition of the
Although treatments exist for these degenerativepresence of strokes can lead to preventive
dementias, their benefits are modest.It's the othermeasures to decrease the likelihood of future
half of the cases which reveal an interesting grab-bagstrokes.Apart from the conditions and diseases
of different underlying causes and, for that matter,already mentioned, the list of potential causes of
treatments.Neurosurgery can be indicated fordementia is longer still. In brief, not every cause of
dementias caused by brain tumors, especiallydementia can be cured or significantly improved, but
meningiomas which are slow-growing tumors thatwithout a thoughtful, thorough, medical evaluation the
respond poorly to chemotherapy or radiation therapy,ones that can be treated could easily go
but can be totally removed in surgical operations.undetected.(C) 2005 by Gary CordingleyGary
Meningiomas are not cancerous, but because spaceCordingley, MD, PhD, is a clinical neurologist, teacher
inside the skull is limited, they cause trouble byand researcher who works in Athens, Ohio.
crowding the brain. Subdural hematomas and epidural