Michael J. Rosner, MD, Peter D’Amour, MD and Peter C. Rowe, MD

Introduction: Correlation of MR findings in those patients with FMS and CF-IDS is difficult, in part due to wide variations in the population carrying these diagnoses. Because the subset of patients with NMH is rigorously defined by tilt table and other objective abnormalities and also may carry the diagnosis of FMS and/or CF-IDS, we analyzed their clinical symptoms, signs and MR findings. The latter was especially of concern since the radiological confirmation of structural disease in the FMS CF-IDS population is often vague, elusive and has significant overlap with asymptomatic patients.

Methods: Patients referred for potential surgical treatment with tilt table proven Neurally Mediated Hypotension (NMH) underwent a standardized interview, neurological evaluation, magnetic resonance (MR) evaluation including CINE MR of the posterior fossa. They also completed a 75 item questionnaire which rated the degree of a spectrum of complaints on a 0-3 scale (0=none, 3=severe) or a visual analog scale with 100 being the most severe possible degree.

Results: Fifteen patients have been evaluated; eleven have undergone craniovertebral decompression; two await surgery:

1. All patients have had resolution of syncope and hypotension. One remains on a low dose of fludrocortisone and a second on a low dose of dexadrine.

2. POTS has also improved or resolved in all cases, but the rate of resolution of the POTS has been slower than that of the NMH. There seems to be a phase of increased sensitivity to endogenous catecholamine release, which also resolves with time. Deconditioning, which is prominent in these patients, may also cause tachycardia, etc., and be confused with symptoms of POTS.

3. Concomitant symptoms of FMS and/or CF-IDS resolve in parallel with normalization cardiovascular responses. These symptoms include cognitive dysfunction, pain syndromes and a broad array of dysautonomic problems.

Complaint	Pre-Op (n=13)			Post-Op (n=5)			Control (n=6)
	Mean	SD	Median	Mean	SD	Median	Mean	SD	Median
Profuse Sweat	1.6	(1.1)	[1.5]	1.0	(0.8)	[1]	0.0	(0.0)	[0]
Dizziness	2.2	(0.9)	[2.5]	1.4	(1.1)	[1]	0.0	(0.0)	[0]
SOB	1.6	(1.1)	[2.0]	1.0	(1.4)	[0]	0.0	(0.0)	[0]
Chest Pain	1.4	(1.2)	[1.0]	0.4	(0.9)	[0]	0.0	(0.0)	[0]
Palpitations	1.1	(1.1)	[1.0]	0.2	(0.4)	[0]	0.0	(0.0)	[0]
Color Changes	1.4	(1.3)	[2.0]	0.8	(0.8)	[1]	0.0	(0.0)	[0]
Overall (0-3)	1.6	(1.0)	[1.8]	1.1	(1.0)	[0.7]	0.0	(0.0)	[0]
Days Felt Good	0.6	(0.9)	[0]	4.0	(4.2)	[3]	6.8	(0.4 )	[7]
Missed Work	5.8	(2.0)	[7]	3.2	(2.2)	[3]	0.0	(0.0)	[0]
Visual Analog (%)
Pain Interferes	88	(13)	[90]	57	(29)	[48]	3	(16)	[8.1]
Severity of Pain	78	(25)	[91]	48	(21)	[47]	1	(17)	[2.2]
Tiredness	91	(9)	[92]	69	(29)	[64]	10	(17)	[17]
Awaken Rested	93	(9)	[96]	67	(31)	[57]	32	(16)	[36]

4. The MR differences between the patients with NMH vs. a group of normal control patients related to the craniovertebral junction region. The foramen magnum was smaller, 35.5 ± 2.7 vs. 39 ± 4.8, p<0.03) and the vertebral vessels impacted the brainstem to a greater degree and more often than controls ((p<0.03). The cerebellar tonsils were lower, 2.0 ± 1.1 vs. 1.25 ± 1.1 (p=0.14), and the C2 canal was smaller, 11.3 ± 4.3 v s. 13.6 ± 1.7 (p=0.07); the latter two differences could have been due to chance.

5. No patient with NMH/POTS had a normal neurological exam. Neurological signs also improved following craniovertebral surgery.

Conclusions:

1. A population of patients with NMH/POTS responds to suboccipital craniectomy and/or cervical laminectomy.

2. If patients carry the diagnosis of FMS or CF-IDS, then these symptoms also resolve in parallel with the cardiovascular symptoms of NMH/POTS following craniovertebral decompression.

3. The MR/radiographic appearance of these patients is characterized by minimal abnormality and can easily be read as “normal.” However, the essential findings are consistent with the hypoplastic posterior fossa and/or congenital-cervical stenosis. There is, as yet, no pathognomonic radiographic change, which allows diagnosis independently of a careful and thorough history and physical examination.

4. While the radiological diagnosis of the hypoplastic posterior fossa can be difficult, the clinical outcome after decompressive surgery warrants a thorough evaluation and aggressive surgical approach.

Presented at the National Fibromyalgia Research Association's Subgroups in Fibromyalgia Symposium, September 26-27, 1999, in Portland, Oregon.

For Appointment Information Contact:

Michael J. Rosner, MD

4550 80 Doctors Drive Suite 4

Hendersonville NC 28392

(828) 684-1076