Thursday May 16, 2013
Researchers at Massachusetts General Hospital considered the neuroanatomy of peduncular hallucinosis, which usually involves very colorful and elaborate visions of people, animals and scenery.
Classically, the symptoms are caused by damage to the midbrain, pons or thalamus. The problem is that in actuality, lesions such as strokes don't usually just hit one little area, but involve more than one region.
The researchers looked at the magnetic resonance imaging of people with strokes that led to peduncular hallucinosis, and seeing what areas of damage these brains had in common.
The main site shared by 22 out of 23 cases was the central thalamus when studying all lesion overlap analysis, in areas called the intralaminar and paramedian nuclei. The right half of the brain was usually involved.
This initial study was followed by special functional MRI studies that showed a connection between this region and areas responsible for visual association in the back of the brain.
This finding ties together what has previously been a seemingly unrelated set of subcortical structures. Furthermore, the findings call into question the usual explanation for peduncular hallucinosis, that it is due to release of inhibition of the posterior visual cortices.
Instead, the researchers suggest that the hallucinations result from a pathological network transition from normal visual processing of the external world to internal visual imagery. Other suggested theories include a release of the dreaming stage of sleep into the waking state.
Tuesday May 14, 2013
I confess that I had high hopes for trials of IVIG in the treatment of Alzheimer's. Preliminary evidence suggested that the medication could be very beneficial. Unfortunately, the results from the large clinical trial have shown no significant benefit between those who were taking the drug and those who were not. There were some significant findings in a group of patients who were positive for the gene ApoE4, but whether these results will be clinically meaningful remains to be seen.
Alzheimer's disease is a personally crushing illness that has the potential to overwhelm healthcare systems in the coming decade as populations age. Despite millions of dollars spent, the disease is stubbornly resistant to all treatments so far. In the face of numerous expensive defeats, many companies are reconsidering whether it is worth further attempts to cure Alzheimer's disease. For those already suffering from the disease, a cure cannot come quickly enough.
Sunday May 12, 2013
Postural instability is a cardinal symptom of Parkinson's disease, and stops many from even walking. Dancing, on the other hand, may be more helpful.
Ann McKee, a fourth year medical student at Emory University, presented results at the 2013 American Academy of Neurology's Annual conference that suggests that 30 hours of tango lessons helped Parkinson's patients with mobility and balance.
Even months after the training ended, benefits were still detectable. Only two participants fell during the 48 classes. All seemed to enjoy the classes as well.
Intriguingly, this isn't the first time dance has been suggested to help with Parkinson's disease. Earlier in March 2013, an Italian neurologist named Dr. Volpe described the benefits of Irish dancing in Parkinson's. He first noticed the effect in a gentleman with Parkinson's disease in 2010. Dr. Volpe suspected the benefit came from the different steps in the dance, which were different from the standard back and forth movement of walking.
Another possible explanation may be the rhythmic music, which could cue the brain to bypass the standard pathway involved with walking. Parkinson's disease involves abnormal rhythms in the basal ganglia, and perhaps the music can interrupt that signal.
Regardless of the reasons, people with Parkinson's disease may have something new to dance about.
Tuesday May 7, 2013
A group has shown that an investigational drug called ecopipam relieved tics in adult patients after just eight weeks. The drug works on dopamine receptors, thereby addressing the neurological network theorized to underlie the symptoms of Tourette's syndrome.
According to Donald Gilbert, MD, MS, of Cincinnati Children's Medical Center, ecopipam reduced measures of tic severity by 20 percent.
Currently, drugs for Tourette syndrome are primarily antipsychotic medications such as haloperidol (Haldol), which can have severe side effects in some patients.
Many of the patients lost weight while taking ecopipram. Three patients had nausea, fatigue and sedation. Two others had insomnia and restlessness. Urges to perform a tic, mood, and obsessive-compulsive behavior was not changed.
These results remain preliminary, and require confirmation by a larger trial.