INTRODUCTION: NMH/POTS clinically and radiologically relate to a hypoplastic posterior fossa and/or upper cervical cord and may be surgically decompressed. OBJECTIVE: Test the hypothesis that symptoms and function will be improved at 12 months after surgery when compared to the same measures obtained preoperatively. METHODS: 50 patients were selected based upon an abnormal tilt table examination defining cardiovascular/autonomic dysfunction, abnormalities identified from the neurological examination and supported by radiographic changes at the foramen magnum and or cervical canal. Patients then underwent decompression of the involved region. They were followed longitudinally with repeat neurological examinations, questionnaires for grading of symptoms including incremental and visual analog scales of outcome and/or symptomatic improvement. Systat 7.0 and Excel were used for data analysis (all values X + SD). Results: Six cardiovascular symptoms including palpitations, SOB, dizziness, non-cardiac chest pain all improved (p= 0.016-0.000009). Related symptoms and physical findings improved.

The number of days/week patients felt “good” increased from 1.0 + 1.5 to 3.9 + 2.3 (p= 1.7E-11) at 12 months; only about 30% of patients were working pre-operatively compared with 77% at one year (p= 0.000015); this was paralleled by a large reduction in “days missed from work.” There were no surgical deaths, nor serious complications. No patient worsened neurologically. CONCLUSION: Patients with NMH/POTS with radiological changes consistent with neurological abnormalities can undergo posterior fossa and/or cervical decompression with important and long lasting improvement in quality of life as measured by assessments of symptoms, their ability to function within the home and workplace, and neurological exams. The risks of surgical decompression should be minimal.

INTRODUCTION: The purpose of identifying posterior fossa and/or cervical cord compression is to provide direction in surgical decompression. Such decompression can be achieved with standard cervical laminectomy and/or forms of posterior fossa craniectomy. However, the array of symptoms with which those with the diagnosis of neurally mediated hypotension (NMH) and/or positional orthostatic yachycardia (POTS) complain is often considered ‘non-anatomical’ and probably psychosomatic in origin by most surgeons and they doubt that significant improvement in well being or function can be achieved for most of these individuals. Symptoms related to NMH/POTS include vague dizziness, syncope, shortness of breath, palpitations, panic attacks, cold hands and feet, abnormalities of perspiration, flushing and others. They frequently include pain, other dysautonomias (bladder dysfunction, GERD, irritable bowel syndrome) and somatic weakness, sensory disturbance, ataxia, etc. OVERALL HYPOTHESIS: Symptoms will improve when compared with those of the preoperative state by 12 months after surgery. Hypothesis statement and testing was of the form: H1: μ1 ≠ μ0 H0: μ1 = μ0

METHODS: 52 patients with the established diagnosis of NMH/POTS were prospectively given questionnaires dealing with their symptoms and ability to perform activities of daily living, including their occupation. The questionnaires were administered preoperatively and at each post-operative visit, typically at 6 weeks, 6 months and 12 months (or longer) after surgery. The questionnaire asked the patients to grade symptom as none, mild, moderate or severe. Other symptoms were graded on a visual analog scale of severity and converted to a 0-100 scale. Data were entered into Excel and/or Systat 7.0 for statistical analysis. Because of the sample size, most analyses were done with parametric statistics such as Student’s t-test for matched pairs. “Not a symptom” was coded as ‘0’; mild symptoms were coded ‘1’; moderate symptoms were coded ‘2’ and severe symptoms were coded as ‘3’. For double checks and entries splitting lines, answers were coded as 1.5, 2.5, etc.

RESULTS: Symptoms (all values X ± SD; [median])

Pain Outcome

Alimentary Symptoms

Fatigue Outcome

DISCUSSION: The cardiovascular symptoms related to NMH/POTS improve in important and consistent ways.  These data suggest that in the patient’s view of himself/herself, pain expressed in numerous fashions and manifestations improves throughout the year after surgery. The relationship of the upper spinal cord and brainstem to cardiovascular symptoms is clear cut, and it is no surprise that gastrointestinal symptoms should also improve: The GI tract is integrated in its activity at the level of the lower brainstem. Improvement in fatigue and the ability to focus and concentrate probably relate to the reticular activating system, which is prominent at this (medullary) level. More importantly than any given ‘symptom’ is the concept that the upper cervical spinal cord/medulla is capable of causing dysfunction in multiple vegetative systems which lead to a plethora of somatic complaints.  All too often, physicians dismiss these complaints as psychosomatic/non-organic/non-anatomic and refer the patient for psychiatric evaluation—a dead end for most.  The brainstem and upper cord are the one area of the nervous system where all of these functions coincide, including pain control. The importance of this issue lies in the ability to improve functional outcome.  By one year, about 78-80% of patients had resumed work.  Pre-operatively, only about 30% were still employed and this was often tenuous.  This figure is paralleled by improvements in feelings of well-being.

CONCLUSIONS: 
1.  Surgical decompression of the posterior fossa and/or cervical spine significantly reduces symptoms associated with NMH/POTS.

2.  Pain and fatigue are associated with NMH/POTS and improve in parallel with the symptoms of NMH/POTS. The reduction in pain, fatigue and multiple other complaints persists and continues to improve through at least the first post-operative year.  “Placebo” effect of surgery is highly unlikely.

3.  The reduction in complaints and symptoms leads to important increases in employment and ability to function both within and without the home environment

 4.  The improvement in patients’ symptoms includes a large improvement in autonomic dysfunction such as the array of GI complaints often called ‘Irritable Bowel Syndrome’, bladder function improves as well as the symptoms associated with NMH/POTS. 

5.  Brainstem and upper cervical cord involvement should be suspected in the face of multiple dysautonomias with or without somatic complaints of numbness, weakness, ataxia, etc.

 Abstract presented at                      National Fibromyalgia Research Association
American Assoc of                          Neurology & New Treatment Modalities in FM
Neurological Surgeons                     Symposium –Portland, OR—Oct 2002
Annual Meeting – 2002