2/21/2025
PITTSBURGH – For some patients born with a certain skull abnormality, unexpectedly early cognitive decline and symptoms of depression and anxiety may be corrected with a brain surgery, report University of Pittsburgh neurosurgeons today in the Journal of Neurosurgery.
For people who are born with Chiari Malformation type 1, or CM1, –– a skull abnormality that pushes the back of the brain down into the opening at the base of the skull –– a surgical intervention may not only relieve classic symptoms like headaches and tingling sensation in hands and feet but may also improve those patients’ memory and psychological health.
“Many clinicians don’t recognize cognitive and psychiatric symptoms as components of a Chiari diagnosis,” said senior author Robert Friedlander, M.D., chair of neurological surgery at Pitt and co-director of the UPMC Neurological 
Institute. “Our study makes it clear that those symptoms should not be ignored and that there is a population of patients who might see significant improvement in symptoms after surgery.”
Patients who present with classic symptoms of CM1 often choose to undergo surgery to reduce excess pressure onto the back of the brain called the cerebellum. During the minimally invasive procedure that can be performed in about two hours by a skilled surgeon, the base of the skull is widened and the cerebellum is repositioned to improve the flow of cerebrospinal fluid and relieve pressure in the brainstem and the spinal cord.
According to an earlier study in people who underwent brain imaging for a variety of health indications, nearly 1% of Americans are estimated have a structural CM1 malformation. Whereas many of those individuals are symptom-free, some suffer from headaches that are especially severe while coughing or sneezing or experience a tingling sensation in arms and feet. Many also report mental health symptoms that are often dismissed.
“Many of the Chiari patients I see in my clinic complain of brain fog. I would hear of similar symptoms so often that I took notice,” said Friedlander. “An otherwise healthy individual between 16 and 40 years of age should not be experiencing cognitive decline. After surgery many patients happily informed me that they felt cognitively improved.”
To establish objective measures of any such improvements, a group of neuropsychologists, led by Luke Henry, Ph.D., assistant professor of neurosurgery at Pitt,performed formal evaluations of psychiatric symptoms and cognitive performance before and six months after the surgery in 54 CM1 patients at UPMC from 2015 to 2023. Those neuropsychological evaluations included measurements of processing speed, attention, memory and executive function, as well as symptoms of anxiety and depression.
Nearly 90% of patients who participated in the study had improvements in their cognitive function or psychiatric symptoms, with approximately one third showing improvements in both.
“Our results show that the surgery alleviates much of the psychiatric distress related to physical symptoms and improves the cognitive problems that the patients present with prior to the intervention,” Henry said. “These observations help us better understand the manifestations of the cognitive dysfunction in these patients and show that a ‘fog’, as patients often describe it, can be lifted.”
Even though additional research is needed to understand the mechanism behind such improvement, clinicians say that the findings underscore the potential role of the cerebellum in cognitive and psychiatric dysfunction.
To further disentangle the association between cognitive and psychiatric symptoms with CM1 disease presentation, Friedlander and his team are planning to launch a follow-up study comparing clinical effectiveness of surgery with hope to better inform patient care.
Other authors of this research are Luke Henry, Ph.D., Michael McDowell, M.D., Amy Byrd, Ph.D., Ricardo Fernández-de Thomas, M.D., Yue-Fang Chang, Ph.D., Kamil Nowicki, M.D., Rohit Mantena, B.S., and Peter Strick, Ph.D., all of Pitt; and J. Brett Crittenden, Psy.D., of Evans Army Community Hospital; and Tina Stephenson, Psy.D., of Chatham University.
This research received no external funding support.
PHOTO DETAILS: click images for high-res versions
Left photo
CAPTION: Robert Friedlander, M.D.
CREDIT: UPMC
Right photo
CAPTION: Luke Henry, Ph.D.
CREDIT: UPMC