Neurosurgeons warn of unnoticed head trauma

NEW YORK — You don’t have to hit your head to develop an insidious bleed between the soft covering of your brain and the brain itself that can threaten your health or life.

The condition, called chronic subdural haematoma (SDH), is becoming increasingly common as the city’s population ages, prompting New York University Langone Medical Center neurosurgeon, Dr Uzma Samadani, to urge her colleagues to gear up for a growing number of cases likely to require neurological intervention.

FORGOTTEN HEAD TRAUMA

Head trauma from a fall or other accident remains an important cause of the disorder, though in one-third to half of the cases, patients cannot recall an injury that might account for it.

In many instances, the trauma was so trivial it was forgotten, like walking into an open cupboard door or hitting one’s head getting in or out of a car.

Indirect trauma that jostles the brain is more common. About half of patients who report having fallen did so without hitting their heads.

Mr James Reilly, 68, is a case in point. In early January, Mr Reilly, who lives in Hoboken, New Jersey, said he fell out of bed while dreaming, and broke a few ribs. But he didn’t hit his head and seemed otherwise fine.

However, two months later, he developed difficulty speaking and using a computer. When his doctor sent him for a CT scan of his brain , itrevealed a chronic SDH.

The lesion was surgically drained at the Veterans Affairs Medical Center in Manhattan, New York, where Dr Samadani is chief of neurosurgery and Mr Reilly is a clerk in the department of neurology and physical medicine. He has returned to his job.

rising chronic sdh cases

The incidence of chronic SDH has been rising steadily since 1967, with one-third of the cases occurring in people over the age of 80.

The condition is much more common among older men with a higher rate of additional risk factors, including heavy drinking or a history of brain injury, Dr Samadani said.

Heavy drinking causes liver damage that can disrupt the blood’s clotting functions, she explained.

Likewise, the chance of developing a chronic SDH is significantly higher among those on anticoagulant medication, such as warfarin, which is commonly prescribed to prevent heart attacks, strokes and blood clots, especially for older adults.

As many as 24 per cent of patients with chronic SDH were on warfarin or an anti-platelet drug to prevent clots, according to a study by researchers in Wales. As many as 10 per cent of patients had a history of alcoholism or epilepsy, the Welsh team reported.

Obesity can be a contributing factor by increasing oestrogen levels in the body, said Dr Samadani.

SHRINKING BRAIN

Old age remains the leading predisposing factor. As people age, the brain shrinks, creating a space in which fluid can collect. The veins that drain the brain must traverse this space, and even the slightest jolt can cause them to leak, leaving blood trapped against the brain.

Also, these bridging veins become more fragile and susceptible to tears.

Chronic SDH has been described as “the great neurological imitator” because it often presents a confusing array of possible symptoms that can resemble, alternatively, a psychiatric disorder, dementia, migraine, epilepsy, Parkinson’s disease, a stroke or a transient ischaemic attack, also known as a mini-stroke.

Patients may develop a rather severe headache and weakness on one side of the body, have difficulty walking, seem confused or have trouble speaking, said Dr Samadani.

She added that chronic SDH “is a common treatable cause of dementia”.

Symptoms tend to develop rather suddenly, often without apparent explanation. Patients and their doctors need to be aware of the various symptoms and signs, and follow up with a CT scan that most often can reveal or rule out a subdural haematoma.

The scan may need to be repeated using a dye if initial results are unclear.

diagnosing SDH

The Welsh team noted that the most important factor in diagnosing chronic SDH was “a high index of suspicion” in patients whether or not they had a head injury or other trauma.

Warning signs include headache, a change in mental status or worsening of pre-existing neurological or psychological illness, as well as neurological problems in a specific location, such as one side of the face, an arm or even a small area of the tongue.

Treatment of chronic SDHs is not always needed, though patients with a seemingly stable haematoma must be monitored and given prompt treatment if symptoms worsen.

If bleeding into the subdural space continues unchecked, it increases pressure on the brain that can lead to a loss of consciousness, permanent disability or death.

when treatment is needed

Only one-third of patients require surgical treatment, Dr Samadani said. In the remaining two-thirds, the haematoma is gradually reabsorbed without invasive treatment. Patients can also be given medication to help speed up the process, she said.

While many chronic SDHs cannot be prevented, the risk of developing one can be lowered by avoiding alcohol abuse, reducing the risk of falls and maintaining a normal body weight.

Although there is no certain way yet to minimise brain shrinkage with age, there may be hope in the form of exercise; in particular, cardiovascular exercise. Dr Steven R Flanagan, chairman of rehabilitative medicine at NYU Langone Medical Center, said that evidence from regular cardiovascular exercise suggests it “increases brain-derived neurotrophic factor”, which promotes survival of the brain’s neurons.

Yet another reason to get — and stay — moving as you grow older. The NEW YORK TIMES