Hello tinglinglegs:
Right-Side Involvement
The now-apparent indication that you had problems with both the right arm and the right leg would indicate something different that a spinal problem (which would be one limb or both R and L extremities). PFO have long been suspected and related to their size (Refs 1-3). While only a leg involvement would indicate a cord problem (probably), a PFO is a suspected occurrence in lateralizing R or L sides. Passage of bubbles through the lung vasculature is also a possibility.
Other Factors In the PFO Story
There is also evidence that the PFO can increase in size with time. This would probably also indicate an increase in hemodynamic significance (i.e., whether it has any real meaning for deleterious medical effects) [Ref 4]. there is also evidence of where in the monthly cycle of a woman diver the incident occurred [Ref 5].
MRI
While it has been reported, “white areas” on an MRI are equivocal. Some divers have them but non-divers do also [Ref 6]. Divers do not seem to have “spots” based solely on the PFO [Ref 7].
A recommendation of very conservative diving is sometimes made and is an alternative to none at all.
Dr Deco :doctor:
References :book: Some modification from the originals
[1] Kerut EK, Norfleet WT, Plotnick GD, Giles TD. Patent foramen ovale: a review of associated conditions and the impact of physiological size. J Am Coll Cardiol. 2001 Sep;38(3):613-23.
Patent foramen ovale (PFO) is implicated in DCS. The autopsy incidence of PFO is approximately 27% and 6% for a large defect (0.6 cm to 1.0 cm). Saline injection via the right femoral vein appears to have a higher diagnostic yield for PFO than via the right antecubital vein. The larger PFOs (approximately > or =4 mm size) or those with significant resting shunts appear to be clinically significant. Approximately two-thirds of divers with unexplained DCS have a PFO that may be responsible and may be related to PFO size. After four cases of serious DCS in EVA simulations, a resting PFO was detected by contrast TTE in three cases. Patent foramen ovales vary in both anatomical and functional size.
[2] Cartoni D, De Castro S, Valente G, Costanzo C, et al. Identification of professional scuba divers with patent foramen ovale at risk for decompression illness. Am J Cardiol. 2004 Jul 15;94(2):270-3.
Functional and anatomic characteristics of patent foramen ovale (PFO) were investigated in 66 professional scuba divers (41 with and 25 without decompression illness) using transthoracic and transesophageal echocardiography. PFO with right-to-left shunting at rest is associated with decompression illness, particularly the neurologic type. A wider patency diameter together with a higher membrane mobility are associated with the risk of developing the disease in divers with PFO.
[3] Torti SR, Billinger M, Schwerzmann M, et al. Risk of decompression illness among 230 divers in relation to the presence and size of patent foramen ovale. Eur Heart J. 2004 Jun;25(12):1014-20.
BACKGROUND: The risk of developing decompression illness (DCI) in divers with a patent foramen ovale (PFO) has not been directly determined in relation to the PFO's size. METHODS: In 230 scuba divers, contrast trans-oesophageal echocardiography (TEE) was performed for size grading (0-3) of PFO. Prior to TEE, the study individuals answered a detailed questionnaire about their health status and about
their diving habits and accidents. For inclusion into the study, > or =200 dives and strict adherence to decompression tables were required.
RESULTS: Sixty-three divers (27%) had a PFO. Overall, the absolute risk of suffering a DCI event was 2.5 per 10,000 dives. There were 18 divers (29%) with, and 10 divers (6%) without, PFO who had experienced > or =1 major DCI events. In the group with PFO, the incidence per 10,000 dives of a major DCI, a DCI lasting longer than 24 h and of being treated in a decompression chamber was 5.1 and was 4.8-12.9-fold higher than in the group without PFO. The risk of suffering a major DCI, of a DCI lasting longer than 24 h and of being treated by recompression increased with increasing PFO size.
CONCLUSION: The risk of suffering a major [neurlogical] DCI parallels PFO size.
[4] Germonpre P, Hastir F, Dendale P, Marroni A, Nguyen AF, Balestra C. Evidence for increasing patency of the foramen ovale in divers. Am J Cardiol. 2005 Apr 1;95(7):912-5.
Using a standardized contrast-enhanced transesophageal echocardiographic technique, a group of divers was reexamined for the presence and size of patent foramen ovale (PFO) 7 years after their initial examinations. Unexpected but significant increases in the prevalence and size of PFO were found, suggesting a possible increasing risk for decompression sickness in these divers over time.
[5] Klien S, Spiegel M, Engelhardt K, Schmidauer C, et al. Menstrual cycle dependent right-to-left shunting: a single-blinded transcranial Doppler sonography study. Undersea Hyperb Med. 2005 Nov-Dec;32(6):403-7.
BACKGROUND AND PURPOSE: Menstruation has been described as risk factor for neurological DCS. In considering this for paradoxical gas embolism, we hypothesized that there may be a link between cycle-dependent hormonal changes and the manifestation of a right-to-left shunt (RLS).
METHODS: 40 women with a regular cycle of 28 days underwent transcranial Doppler sonography examinations (TCD) on day 1 and on day 15 of the menstrual cycle [to indicate] a RLS.
RESULTS: We found a 25% RLS incidence consistent with the literature. In 7 of 10 shunt-positive women it was detected mainly or exclusively on day 15. This difference in PFO detection rate is statistically significant, indicating more RLS during the peri-ovulatory period.
CONCLUSIONS: Our results do not support menstruation as a risk factor for neurological DCS.. Factors that increase the risk for developing a RLS and thereby paradoxical embolism should be avoided, perhaps including diving during the peri-ovulatory period of the menstrual cycle. Furthermore, contrast PFO testing in fertile females may be most sensitive if conducted mid-cycle.
[6] Rinck PA, Svihus R, de Francisco P. MR imaging of the central nervous system in divers. J Magn Reson Imaging. 1991 May-Jun;1(3):293-9.
A group of 70 professional divers and 47 healthy control subjects who had never dived were examined with magnetic resonance (MR) imaging to determine the prevalence of focal white matter changes in the brain. Spots of high signal intensity in white matter on proton density- and/or T2-weighted spin-echo images were detected in 42% of the control subjects and in 34% of the divers. In the
control subjects, the prevalence of more than three changes was related to smoking, use of alcohol, head trauma, age of more than 35 years, and a combination of several cerebrovascular risk factors. This relationship was not present in the divers. The prevalence of changes in divers was inversely related to diving depth, amount of diving, participation in "unsafe diving," and decompression sickness. The reasons for these results could not be ascertained.
[7] Koch AE, Kampen J, Tetzlaff K, Reuter M, et al. Incidence of abnormal cerebral findings in the MRI of clinically healthy divers: role of a patent foramen ovale. Undersea Hyperb Med. 2004 ;31(2):261-8.
BACKGROUND: To investigate incidence and number of abnormal cerebral hyperintensities (ACFs) in Magnet Resonance Imaging (MRI) and its relation to a patent foramen ovale (PFO) in divers with no history of decompression illness.
METHODS: Cohort study on 50 divers (21-5500 dives). Incidence and number of ACFs were visualized by cranial MRI and size of a PFO by echocardiography and transcranial Doppler ultrasound (TCD) with echocontrast.
RESULTS: A total of 137 ACFs was found in the 50 subjects,; but after correction for age, the remaining correlation did not reach significance. In 18 divers, a PFO was present by either the application of echocardiography or TCD; in 12 divers, the PFO was of high hemodynamic relevance. Ten of 18 divers with a PFO had at least one ACF, while in the remaining 32 divers, only 14 had at least one ACF (56% versus 44%, not significant). Seven of 14 divers (50%) with 4 ACFs had a PFO, compared to 11 of 36 (31%) with less than 4 ACFs (p = NS). CONCLUSION: In this cohort of healthy divers, no significant association was found between PFO presence and incidence or number of ACFs.
