Medical tests

A medical test is any kind of diagnostic procedure performed for health reasons. Each subject with a leading complaint of persisting perception disturbances needs a full diagnostic work-up including ophthalmologic, neurological and psychiatric examinations as well as CAT or MRI scans of the brain. The most important medical test for the diagnosis of persistent aura without infarction is the taking of the medical history, notably the history and family history of migraine and drug use, obtaining a detailed account of the chronology of symptoms as experienced by the patient.

Blind men and an elephant (see here).

Of the 60 subjects with a diagnosis of definite persistent aura without infarction, only 37 reported having visited one or more ophthalmologists (subjects #1, #20, #23, #30, #45, #52, #75, #86, #120, #136, #138, #141, #142, #145, #147, #157, #162, #171, #180, #185, #189, #200, #217, #228, #230, #233, #234, #258, #264, #265, #273, #276, #277, #284, #300, #296, #301), 34 one or more neurologists (subjects #1, #8, #20, #23, #30, #45, #52, #73, #80, #85, #86, #141, #145, #147, #152, #156, #159, #162, #167, #168, #169, #171, #180, #189, #254, #258, #264, #265, #273, #276, #277, #284, #300, #301), 12 an ENT doctor (subjects #23, #45, #145, #153, #162, #172, #189, #228, #264, #265, #273, #296), 8 a neuro-ophthalmologist (subjects #52, #138, #142, #145, #159, #179, #277, #301), 7 a "Lyme literate" doctor (subjects #142, #147, #171, #179, #183, #200, #264), 3 an oto-neurologist (subjects #157, #172, #185), 2 a psychiatrist (subjects #73, #175), 2 a child psychiatrist (subjects #45, #273), 2 a psychologist (subject #171, #276), 2 a chiropractist (subject #264, #276) and each one an orthopaedist (subject #265), a child psychologist (subject #235), an optometrist (subject #147) and an optician (subject #80), respectively. Overall, only 50 subjects (#1, #8, #20, #23, #30, #45, #52, #73, #75, #80, #85, #86, #120, #136, #138, #141, #142, #145, #147, #152, #153, #156, #157, #159, #162, #167, #168, #169, #171, #179, #180, #185, #189, #200, #217, #228, #230, #233, #235, #254, #258, #264, #265, #273, #276, #277, #284, #300, #296, #301) – 83,3 % of the sample - had been examined by a medical specialist, indicating an insufficient health care utilization by sufferers from persistent aura.

HenrikKJ [subject#074], Normal MRI images, 2008. © 2008 HenrikKJ (for larger image see here)

A total of 45 subjects had a CAT (subjects #20, #30, #52, #75, #147, #152, #153, #162, #180, #185, #217, #258, #264, #277, #300, #301) and/or MRI scan (subjects #1, #8, #14, #20, #23, #30, #45, #52, #73, #85, #86, #120, #138, #141, #142, #145, #147, #152, #156, #157, #159, #162, #167, #168, #169, #171, #172, #175, #179, #180, #185, #189, #234, #254, #264, #265, #277, #284, #296, #300, #301) of the brain.

Only six of these neuroradiological examinations yielded a pathological finding (which prompted starrant [subject #138] to comment that "It kind of stinks that something so debilitating is yet so small that it can't be detected"). One subject (#75) recalled: "If I remember correctly, something shows a perfusion problem with my left hemisphere". Unfortunately, it was not possible to obtain a copy of the neuroradiologist's report on this CAT finding. One subject (#152) reported her MRI showing "punctate T2 signal intensities in subcortical areas of white matter". T2-hyperintense foci are one of the most frequent findings in cerebral magnetic resonance imaging. They can pose serious diagnostic problems which is reflected by their English name and abbreviation - UBOs (Unidentified Bright Objects). Although it seems that cerebral white matter lesions are more common in migraineurs than in the general population (Kruit et al., 2004), the nature, association and the clinical significance of these cerebral white matter lesions of migraineurs are not yet conclusive (Dahlof et al., 2005). The MRI of another subject (#189) showed just a single UBO: "Everything was normal except MRI which was 'almost' normal but had a small anomaly that my neurologist thinks is absolutely nothing, the neuroradiologist thinks might be demyelineation or a vascular deformation (or nothing), and I fear could be evidence of CJD" (Creutzfeld-Jakob disease). The last mentioned remark showed that unwarranted interpretations of such UBOs may nurture iatrogenic fears of the patient. The MRI of another subject (#264) showed a single UBO left high frontal in addition to a megacisterna magna, the latter representing an anatomical variant without clinical significance. The MRI of yet another subject (#284) showed "small bright spots" (= UBOs), "but not diagnosed with MS". In one subject (#254), the MRI showed "No significant results, despite the presence of an arachnoid cyst... overlaying the left cerebellar hemisphere".

SPECT examinations were performed in 2 subjects (#138, #254) with normal results.

This image is one of the first EEGs, appearing in Hans Berger's (1929) first publication on EEG (see here).

EEG recordings were done in 17 subjects (#1, #8, #20, #23, #30, #45, #52, #86, #162, #171, #172, #175, #258, #264, #277, #300, #301). In one subject (#175), the EEG showed "some photosensitivity". This 18-year-old female had a history of 2 generalized epileptic seizures at the age of 14 and 18, respectively. "I have been diagnosed epileptic (2 full out tonic clonic seizures)... Both seizures were the same, as described above, and both were witnessed by sane, reliable adults who described them in detail to medical professionals." In one subject (#8), "One doctor say my EEG is mildly abnormal, but another say it is 'nothing impressive', i.e. normal." One subject (#277) got "3 EEGs - majority of neurologists say abnormal activity in left temporal lobe, and some in right. However, MGH epileptologist says normal and that neurologists who don't specialize in seizures would read it as abnormal. So not sure if normal or abnormal but I've never had an actual seizure like alteration in consciousness or spaced out." Similarly, another subject's (#301) EEG was considered by her neuro-ophthalmologist as showing "a lowered seizure threshold" with "complex partial seizure activity in right occipital and temporal lobe", but her neurologist "said my 48 hour EEG was normal so he thinks the lowered seizure threshold diagnosis is wrong". Sleep deprived EEG was recorded in further 2 subjects (#23, #86), with normal result in one (subject #86) and abnormal finding in the other (subject #23). VEPs were recorded in 7 subjects (#20, #145, #159, #171, #189, #264, #301) with normal result. BAEPs were measured in 3 subjects (#189, #264, #301), also yielding a normal result. Likewise, SEPs to median and tibial nerve stimulation were normal in 2 subjects (#264, #301).

References

Berger H. Über das Elektrenkephalogramm des Menchen. Archiv für Psychiatrie 1929; 87:527-570. (Berger H. On the Electroencephalogram of Man. Electroencephalogr Clin Neurophysiol 1969; Suppl 28: 37-73.)
Dahlof CG, Linton-Dahlof P, Lainez JM, Pascual J. [Is migraine a progressive cerebral disease?] [Article in Spanish]. Neurologia 2005; 356-365.
Kruit MC, van Buchem MA, Hofman PA, Bakkers JT, Terwindt GM, Ferrari MD, Launer LJ. Migraine as a risk factor for subclinical brain lesions. JAMA 2004; 291: 427-434.
Rocca MA, Ceccarelli A, Falini A, Colombo B, Tortorella P, Bernasconi L, Comi G, Scotti G, Filippi M. Brain gray matter changes in migraine patients with T2-visible lesions: a 3-T MRI study. Stroke 2006; 37: 1765-1770.
Sonnenberg A. The end of diagnosis: when to stop testing. The American Journal of Gastroenterology 2002; 97: 2494–2498. [For a full reprint see here].

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