Erratic Behavior: Some Causes


MANY BEHAVIORS considered strange or inappropriate, such as hysterical crying, overwrought anger, obsessions, depression and mania, can sometimes be traced to frontal lobe damage, degeneration or disease. But because brain cells cannot be examined directly—and brain imaging is rarely able to detect problems—frontal lobe diagnoses are very susceptible to error.

Such behaviors can be either wrongly attributed to mental illness (and thus inadequately treated) or traced incorrectly to frontal lobe impairment, leading to severe consequences for the sufferer.

“Executive functions”—planning, motivation, inhibition, emotions, and creativity—are behaviors controlled by the frontal lobe.  Say, for example, a dental patient, at the first twinge of pain, slugs the dentist. It may be because of an impairment in the part of the brain that would ordinarily inhibit such a reaction, based on the patient’s knowledge that treatment is necessary.

Head trauma, including post-concussive syndrome and traumatic brain injury, is the most familiar cause of frontal lobe dysfunction. In what are known as “deceleration” injuries, sudden impact causes the brain to be knocked powerfully back and forth inside the hard skull. The result, a sort of bruising, can cause brain swelling and bleeding and lead to lasting damage.  It can either heal with intense therapy over time—more slowly depending on the victim’s age—or can be irreversible.

Frontal lobe degeneration and disease make for trickier diagnoses.  Frontotemporal dementias (FTDs) are the most common forms of dementia in people under 60; and FTDs affect as many people in the 45-64 age group as Alzheimer’s Disease (AD).  Early symptoms include “a disregard for social conventions, impulsivity, apathy, loss of sympathy or empathy…poor insight, planning and assessment,” according to the University of California at San Francisco Memory and Aging Center.

Estimates of false positive FTD misdiagnoses range between 50-69%, usually by general practitioners and most often in younger patients who are in fact suffering from depression or alcohol abuse.  Average life expectancy is 7-13 years after the first FTD symptoms, so that an individual’s ongoing survival can be the only indication of incorrect diagnosis.  Moreover, an FTD diagnosis can make patients vulnerable to others taking control of their care and in some cases obtaining court-ordered guardianships that can be difficult to reverse.

Missed cases—false negatives—of FTD are most often incorrectly labeled AD, Parkinson’s or Huntington’s Disease, or progressive aphasia—the loss of ability to express or understand speech.

Frontal-lobe epilepsy, the second most common form of epilepsy, can also cause emotional symptoms, from sudden fear or a sense that something terrible is about to happen to feelings of anger, range, sudden joy or happiness. Although seizures commonly include movements—grimacing, flailing, bicycling legs—these can occur while the sufferer is completely unaware (called “complex partial seizures”) or aware but unable to move or speak.

A syndrome known as PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections), in which the body’s immune reaction to strep—and possibly other infections like Lyme Disease—attacks frontal lobe brain cells.  PANDAS occurs most often in children, but a Beverly Hills psychiatrist reports diagnosing one to two adult cases each week.

The syndrome can cause obsessive-compulsive behaviors, known as immune-mediated OCD, as well as tic disorders (Tourette’s syndrome), which can appear suddenly, sometimes overnight, during or after the infection.  Also “children may also become moody or irritable, experience anxiety attacks, or show concerns about separating from parents or loved ones,” according to the National Institutes of Mental Health PANDAS fact sheet.

Frontal lobe disorders can be focal, affecting a small area, and can include stroke, Huntington’s Disease, infection and PANDAS. But most are diffuse, creating different clusters of symptoms in individual patients.

The unpredictability and sometimes unknowability of which regions are affected can make impairment difficult to assess and treat. On the other hand, in some cases, deficient executive functions—particularly inhibition—have led to a blossoming of previously unknown artistic talent.

—Mary Carpenter

Every Tuesday in this space, well-being editor Mary Carpenter reports on health news we can use.

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