It seemed as if everyone who worked at our local hospital knew Jake. A self-proclaimed “recovered hater of doctors,” he became a fixture, volunteering in the emergency room. The wisecracking 86-year-old’s wrinkled face, slumped shoulders, and insightful irreverent remarks provided a potent remedy for long, painful ER visits. He had been my patient for less than a year when he came to my office and repeated the same story I had heard in each of his past several visits because he could not remember telling me.
“Doc, I always feel as if I’m removed from my surroundings,” he complained. “I feel, as the kids today say, ‘out of it.’ ” As always, he exaggerated the enunciation of “out of it” as though he were speaking to someone with limited proficiency in English. He had made two visits to the emergency room as a patient after transient episodes of confusion accompanied by diffuse weakness and unsteadiness that made him unable to stay on his feet. During these episodes, he felt even more dissociated from the world around him. The second episode caused him to fall and strike his head against the closet door in his bedroom, but he did not lose consciousness.
Our bodies go to great lengths to preserve blood flow to our most vital organs. To make sure the brain gets enough blood, baroreceptors in the carotid arteries in the neck monitor blood pressure. When we stand up or lose blood volume through bleeding, sweating, or not taking in enough liquids, the pressure drops and the receptors send signals through our autonomic (involuntary) nervous system to increase the heart rate and the smooth muscle tone in our arteries, which brings up the blood pressure and forces more blood to the brain. We call this series of events the baroreceptor reflex, which, as with most of our reflexes, slows with age. Jake habitually maintained a nice low-normal blood pressure, a desirable feature in a human body because low-pressure circulation preserves organ function, most notably in the heart, brain, and kidneys. The price those with healthy low blood pressure pay is that they are more prone to not being able to get enough blood up to the brain when they become hot, drunk, or dehydrated, which leads to spells of lightheadedness or fainting.
Jake’s low blood pressure and slow baroreceptor reflex did not give us an adequate explanation for his troubles. His episodes did not seem to be associated with position change or factors that would lower his blood volume, and his symptoms did not dissipate quickly, although they did resolve in less than 24 hours without leaving any permanent deficits in his function. The next logical potential culprit was his heart. Temporary heart-rhythm disturbances can cause the heart to beat too fast or too slowly for brief periods. When it beats too fast, the heart’s left ventricle does not have enough time between beats to fill with blood, so it pumps out too low an output of blood through the aorta to provide adequate pressure. If it beats too slow or not at all, the cardiac output is again too low to maintain sufficient pressure. Jake had never had any heart problems, but he did smoke a daily pack of cigarettes for about 40 years before quitting in the early 1980s, and smoking does cause damage that predisposes smokers to heart-rhythm problems.
We monitored Jake’s heart rhythm in the hospital overnight after his second emergency-room visit, and his rhythm was as perfect as the timing of his punch lines. All this left us with was a working diagnosis of transient ischemic attacks (TIAs), which are events in which a part of the brain, most likely the cerebellum in Jake’s case, temporarily loses its blood supply and then regains it. Clots breaking loose from the heart and the carotid arteries can cause these events, so we treated him with a capsule containing two drugs, aspirin and dipyridamole, that prevent platelets, the blood cells that start blood-clot formation, from aggregating as they do to start a clot; the manufacturer of the capsule cleverly named it Aggrenox. Jake did not have any more of these episodes after starting the medication, but he still felt a bit as though he were not part of this world.
Jake was also losing his short-term memory, his balance, and his ability to control his urine. Six months earlier, after hearing these complaints for the first time, I had recalled the mnemonic MAI (memory loss, ataxia, incontinence) I had memorized during my medical school neurology clerkship so that I would recognize patients with normal pressure hydrocephalus (NPH). MAI was easy to remember because it was also the name of a group of two bacteria in the tuberculosis family (mycobacterium avian intracellulare) that infect victims of AIDS and other diseases that destroy the immune system. People with NPH have enlarged cerebral ventricles, the spaces within the brain that contain cerebrospinal fluid (CSF). The enlargement results from the brain’s adaptation to diminished CSF resorption through the arachnoid villi, which lines the ventricles. Because there is a corresponding decrease in brain mass, the fluid pressure remains normal, which is why people with NPH do not complain of increasing headaches. I had ordered a CT scan of Jake’s brain, hoping to find NPH, because many patients with it benefit from surgical placement of a catheter (shunt) that conducts the extra fluid from the brain to the heart or to the peritoneum, the cavity where the intestines reside in the abdomen.
Unfortunately, Jake’s scan showed minimally enlarged ventricles consistent with a normal 86-year-old brain, and the diffuse brain atrophy typical of advancing Alzheimer’s disease, so I treated him with donepezil (Aricept), a drug that slows memory loss in people with Alzheimer’s dementia. Donepezil inhibits the enzyme that breaks down acetylcholine, an important neurotransmitter affecting many organs, including the bladder, but it did not help Jake’s overactive bladder, so I later prescribed oxybutinin, which prevents bladder spasm and incontinence.
The purpose of today’s visit was to see how he was doing. One of the challenges of evaluating people with dementia is figuring out whether treatments are working. We can administer tests in the office to assess their mental status, but other intermittent or vague symptoms are tricky. Because they don’t make new memories, they can’t remember what their condition was before the treatment started, so subjective comparison between then and now is difficult. Many elderly people with mild to moderate memory loss live alone, so there is not a reliable source to give us this information, forcing us to rely on pharmacies and visitors to tell us whether they are taking their medicines and how their condition is changing over time. As the memory worsens, demented people can’t remember what medicines or treatments they are using, let alone whether they are working.