Here’s what to be aware of when it comes to potential magnetic interference for your patients who have VP shunts.
At 73 years old, Dorothy Sorlie found that some of her life skills were beginning to disappear, such as writing, walking and swimming. She even had to sign a paper that would allow her husband to sign her name for her. “I knew something was wrong,” she explains in a post for the Hydrocephalus Association. Even her primary care physician could see that this was more than just natural aging. After meeting with several specialists, she finally was referred to a neurosurgeon who told her that she had an advanced case of normal pressure hydrocephalus (NPH).
Normal pressure hydrocephalus, a brain disorder caused by the build-up of cerebrospinal fluid (CSF) in the ventricles of the brain, can cause a myriad of symptoms. Some NPH symptoms such as forgetfulness, difficultly walking, and bladder control problems resemble those of Alzheimer’s and Parkinson’s disease, which can lead to misdiagnosis or written off as normal aging. NPH can also cause psychiatric and emotional changes that may prove challenging for both patients and caregivers.
NPH can be classified as idiopathic NPH (iNPH), typically affecting those over age 55 with no known cause, and secondary NPH, which can occur at any age and can be caused by conditions such as subarachnoid hemorrhage or infectious meningitis.
In one study that followed 35 iNPH patients over two years, researchers found that 71% of the patients presented with some type of psychiatric condition, particularly anxiety and depression, among other psychotic syndromes. In another study of 64 iNPH patients published in Behavioural Neurology, 42% had symptoms of global cognitive impairment.
Here are some cognitive and emotional normal pressure hydrocephalus symptoms:
A study of neuropsychiatric symptoms of 64 iNPH patients found that 70.3% suffered from apathy compared to only 4.8% of the general elderly population. These NPH symptoms include low energy, decreased motivation, decreased interest, and a lack of concern. Apathy is believed to be induced by changes to the anterior cingulate cortex and thalamus.
Executive Function Impairment
This type of mental decline includes executive dysfunction such as problems with planning, organizing, multitasking, processing speed, and decision making. A study of 101 patients found that iNPH patients suffered particularly from severe attention impairment and psychomotor speed.
A second study examined patients on the basis of a Mini-Mental State Examination (MMSE) score, and divided their 11 patients into those with dementia and those without. They found that there tend to be two cognitive profiles in iNPH patients: those who are at a lesser stage of the disease and have isolated frontal lobe dysfunction, and those who have a more advanced form of the disease and have severe global cognitive dysfunction.
However, those in the non-demented group were found to struggle particularly on attention tasks, suggesting that their cognitive deficits are similar to those with fronto-subcortical dementia as seen in Parkinson’s disease.
NPH symptoms such as anxiety can present as both physical and/or emotional, and include numbness, tingling, shaking, heart pounding, indigestion as well as several others. Emotionally, patients are impacted by feelings of nervousness, fear of losing control, and an inability to relax. In the same study mentioned above, 25% of patients were found to be affected by anxiety.
An additional study that compared the presence of anxiety in NPH patients that were admitted to psychiatric facilities versus dementia centers found that it was significantly greater in the psychiatric patients (38.1% vs. 12.5%). Anxiety is thought to be induced in NPH patients by a decline in the orbitofrontal area.
Normal Pressure Hydrocephalus and Depression
While studies vary, it is believed that anywhere from 14% to 46% of NPH patients suffer from depression. Such NPH symptoms include irritability, fatigue, withdrawal, sadness, and an inability to eat or sleep. Brain imaging studies have shown that depression can be associated with right dominant brain dysfunction.
Other Psychological Normal Pressure Hydrocephalus Symptoms
A 2018 study of neuropsychiatric abnormalities in 153 NPH patients was able to analyze the Cambridge Behavioral Inventory results of 41 patients and observed that 70.7% experienced abnormal behavior and 73.2% experienced changes in mood. Three patients were found to have some sort of psychiatric illness involving delusions, hallucinations, and symptoms of bipolar.
Given the wide range of cognitive and emotional changes that NPH patients may experience, it can be helpful to have some tips and tricks to help both the patients and caregivers cope with changes in cognitive functioning, emotions and mood changes.
In a recent talk for the Hydrocephalus Association, Dr. Krista Hanson, a faculty neuropsychologist in the Department of Neuropsychology at Barrow Neurological Institute, outlined helpful strategies to compensate for these potential shortcomings.
For cognitive processing changes:
- Use glasses and hearing aids as needed
- Eliminate outside distractions when trying to learn or remember something
- If necessary, make a list of most important accomplishments, middle-tier accomplishments, and tasks that can be put off for another day
- Consult with a neuropsychologist to identify areas of strength/weakness
For changes in executive functioning:
- Make lists
- Schedule activities
- Break down more difficult tasks into smaller components
- Figure out what time of day you function best and complete the most demanding tasks then
For memory changes:
- Organize or group information
- Connect new information to prior knowledge
- Identify main points
- Write information down and take pictures
- Set alarms
For emotional changes:
- Consider attending counseling, cognitive behavioral therapy (CBT) or mindfulness sessions
- Learn to accept the changes that are occurring and any meaningfulness behind them
- Explore medication management if necessary
- Find low-stimulation environments
- Exercise to naturally release endorphins and boost mood (consult with physician first)
Researchers tracked neuropsychological improvements one year following treatment in a study of NPH patients at five sites in the Adult Hydrocephalus Clinical Research Network in the U.S. and Canada. In the study, 193 NPH patients underwent shunt surgery to drain the excess fluid. Twelve months later, patients’ median score on the Beck Depression Inventory decreased from 11 to 4, with higher scores indicating depression severity.
There is currently an extensive multicenter, prospective, blinded, placebo-controlled clinical trial under way to provide evidence for the efficacy of shunt surgery with iNPH patients. The study will compare placebo versus active shunting outcomes at three-month intervals after surgery, evaluating gait, neuropsychological symptoms and CSF biomarker analysis.