Saturday November 30, 2013
It's the holidays, traditionally a time to focus on the things that make us happy. Raindrops on roses and whiskers on kittens, that sort of thing. Maybe it's Grinch-like of me, but on this holiday weekend I'm writing about what I think is actually my least favorite thing... brain cancer. How like cancer to come when least welcome.
I've seen a lot of bad diseases in neurology, and I can't even definitively say that brain tumors are the worst of them, but for some reason there's something about cancer that particularly frustrates and angers me. Maybe it's a sense of betrayal by one's own body. Maybe it's that so many cancers have resisted our best efforts to treat them. Maybe it's that brain cancer seems so indiscriminate in its victims.
The truth is, though, not all brain cancer make me this angry. Meningioma, for example, is a kind of tumor that is usually treatable, and often doesn't need treatment at all.
The real problem begins in gliomas, when the glial cells meant to support neurons go bad. Even here, some gliomas are better than others. Oligodendrogliomas are often more treatment responsive than many astrocytomas, for example. The worst of the primary brain tumors is grade IV astrocytoma, also known as glioblastoma multiforme, or GBM.
Even aggressive treatment with neurosurgery, radiation and chemotherapy does frustratingly little to help the average quality or quantity of life of someone with malignant gliomas like GBM.
There is some glimmer of hope, though. Genetic markers can label which malignant gliomas respond better to particular treatments, hopefully heralding a time of more targeted therapies with fewer toxic side effects. For those with these aggressive tumors, such personalized medicine cannot come quickly enough.
Thursday November 28, 2013
Facial Onset Sensory and Motor Neuronopathy (FOSMN) is a very rare disorder. In fact, fewer than 20 cases have been reported in the scientific literature so far, including the cases described in 2006, when the syndrome was first described. Briefly, patients first developed paresthesia and numbness in the face, which then spread to the scalp, neck, arms and upper trunk. Later, cramps, fasciculations, and slurred speech developed. Autopsy was done on one patient in 2006, which showed loss of neurons in the brainstem and spinal cord in a fashion similar to amyotrophic lateral sclerosis, though also impacting sensory nerves. The disease seems quite serious, as patients lose their ability to speak or swallow safely. The cause is unknown, though some have suggested a possible autoimmune component, as one case has responded to immunotherapy.
Hokonohara T, Shigeto H, Kawano Y et al. Facial onset sensory and motor neuronopathy (FOSMN) syndrome responding to immunotherapies. Journal of the Neurological Sciences. (Vol. 275, Issue 1, Pages 157-158
Vucic S, Tian D, Siao Tick Chong P, et al. Facial onset sensory and motor neuronopathy (FOSMN syndrome) a novel syndrome in neurology. Brain (Vol. 129, Issue 12, Pages 3384-3390)
Tuesday November 26, 2013
Neurologists like to figure out where things come from. Specifically, if there is a symptom, we like to find a place in the nervous system that is necessary for that symptom to occur.
Sometimes this leads to thinking that is oversimplified. The brain is complicated, and so are our thoughts and feelings. To say that there is one spot in the brain for such a thing as gratitude, for example, would be misleading.
That said, there are regions of the brain that are needed for something like gratitude to occur, and researchers recently described one such area.
The researchers investigated over 60 healthy people by giving them a task in which they were to describe their response to interacting with a friend in different scenarios This allowed the researchers to assign a scale as to how likely the participant was to describe the scenario in a prideful, grateful, guilty or angry fashion. MRI scans of all the participants were then compared.
People who were more likely to respond in a grateful fashion had increased volume in the right temporal lobe. This area has been found to be diminished in a subtype of frontotemporal dementia, a disease that slowly robs people of their normal personality. The right temporal type of frontotemporal dementia frequently leads to colder and less empathetic personality changes.
The authors also found that the posterior cortex, normally associated with visualization, also seemed to be important in moral sentiment such as gratitude. This may be due to a need to imagine a scenario clearly in order to generate empathy, for example.
The overlap between regions of the brain normally associated with empathy and areas associated with gratitude is interesting to me. Perhaps this region actually just stores information regarding social rules in general? Or maybe a degree of empathy is necessary in order to feel grateful-- for example, in order to recognize what giving you something has cost someone else.
Roland Zahn,Griselda Garrido, Jorge Moll, and Jordan Grafman. Individual differences in posterior cortical volume correlate with proneness to pride and gratitude.Social Cognitive and Affective Neuroscience Advance Access, epub October 28, 2013
Friday November 22, 2013
Neurologists have known for a long time that there seems to be a connection between obesity and migraine. Last month this relationship was confirmed even for those who get migraines occasionally. In that study, 3,862 people filled out surveys on height, weight and migraines. Obese people were 81 percent more likely to have episodic migraine compared to people of normal weight. This link is strongest in people under the age of 50. This is actually good news, as migraine is a preventable risk factor, and gives many people a new way to get their migraines under better control.