Shocking colours - ECT temporarily improves colour perception in a colour-blind patient
Brain stimulation – April 28, 2020
Source: OpenAlex
Summary
Electroconvulsive therapy dramatically improved color perception in a woman with severe Major Depression. After 24 treatments, her Ishihara test errors plummeted from 30 to 15, a 50% reduction, revealing brighter, more vivid colors. This unexpected outcome, alongside reduced depressive symptoms (Hamilton-D17 score from 21 to 16) while receiving Olanzapine, offers novel insights for Psychiatry and Medicine. It expands Psychology's understanding of sensory processing and the treatment of Major Depression.
Abstract
Electroconvulsive therapy (ECT) is often the last resort in medically treatment-resistant patients. The mechanisms of its efficacy are still somewhat poorly understood. However, it is clearly a highly effective treatment for severe and psychotic depression, as well as other severe neuropsychiatric conditions [[1]Weiner R.D. Reti I.M. Key updates in the clinical application of electroconvulsive therapy.Int Rev Psychiatr. 2017; 29: 54-62https://doi.org/10.1080/09540261.2017.1309362Crossref PubMed Scopus (67) Google Scholar]. This case-report attempts to offer a perspective on the impact of ECT on sensorial perceptions, transgressing the well-described cognitive effects. A 30-year-old woman was hospitalised due to moderate depression with suicidal ideation (Hamilton Depression Scale 17-items: 21) six months after the birth of her first child. Treatment with 75mg venlafaxine was inadequate; the depression rapidly worsened during hospitalisation, and 10mg olanzapine was added due to psychotic symptoms. She consented to ECT. She is red-green colour-blind (deutan) as her father and all her mother's brothers. After a few ECT treatments, she experienced seeing new colours e.g. during a walk in the hospital gardens, being able to see the red berries in the fall foliage and in the watercolour paintings she herself had previously done. She reported better colour discrimination and that all colours seemed stronger and brighter during the hours following ECT. However, her vision would be back to habitual state the following morning. Since we have not been able to find reports of improvements in colour perception following ECT or other forms of brain stimulation in previous literature, we performed an Ishihara colour blind test before and after ECT. All 38 Ishihara colour plates (Handaya, Japan) were presented 75 cm away under a 6500K lamp (A60, LIFX, Australia). ECT was administered with bitemporal electrode placement, dose titration ½ of age, pulse width of 0.5–1.0msec, stimulus duration of 6–8sec, a 30–70Hz frequency, and with thiopental anaesthesia. On her first Ishihara test the day before her 23rd ECT-session, she made 30 mistakes, which confirmed she was indeed severely red-green colour-blind. Four days later, 1 h after her 24th ECT-session, we re-tested her, and she made 15 mistakes and again expressed that all colours were brighter and more vivid. She reported no other side effects from ECT and received a total of 26 moderately successful ECT treatments as an in-patient and was discharged with fewer depressive symptoms (Hamilton-D17: 16). She continued out-patient treatment with 150mg venlafaxine and 7.5mg olanzapine in an affective disorder clinic. Congenital colour vision defects are present in up to 8% of men, but only 0.5% of women. Commonly, deuteranomaly, which is due to a mutated form of the medium-wavelength pigment that is shifted towards the longer (red) end of the spectrum resulting in reduced sensitivity to green light. To our knowledge improvements in colour perception have not previously been reported after ECT, other forms of brain stimulation, or anaesthesia: Contrarily, defects are observed. Visual phenomena occur during epileptic seizures, e.g. when including the occipital region; epilepsy does not per se affect colour vision and retinal function. The only postictal visual phenomena reported is transient postictal blindness, which is a rare phenomenon seen mostly in children and may be related to the relative electrical instability of the occipital cerebral cortex [[2]Kosnik E. Paulson G. Laguna J. Postictal blindness.Neurology. 1976; 26 (248–248)https://doi.org/10.1212/wnl.26.3.248Crossref PubMed Scopus (43) Google Scholar]. It has been observed a rare transient adverse effect immediately after ECT [[3]Sonavane S. Bambole V. Bang A. Shah N. Andrade C. Continuation of ECT after recovery from transient, ECT-induced, postictal cortical blindness.J ECT. 2012; 28: 48-49https://doi.org/10.1097/yct.0b013e318223c082Crossref PubMed Google Scholar] and general anaesthesia. Antiepileptic drugs are known to result in visual disturbances, particularly colour vision defects [[4]Verrotti A. Lobefalo L. Tocco A. Spalice A. Gallenga P. Chiarelli F. et al.Color vision and macular recovery time in epileptic adolescents treated with valproate and carbamazepine.Eur J Neurol. 2006; 13: 736-741https://doi.org/10.1111/j.1468-1331.2006.01213.xCrossref PubMed Scopus (9) Google Scholar]. ECT cannot change the spectrum of the pigments. However, there might be changes in colour perception at the retinal level induced by seizures through efferent innervation [[5]Honrubia F. Elliott J. Efferent innervation of the retina.Arch Ophthalmol. 1968; 80: 98https://doi.org/10.1001/archopht.1968.00980050100017Crossref PubMed Scopus (57) Google Scholar]. However, these centrifugal axons are few, and their role is debated [[6]Ortiz G. Odom V.J. Passaglia C.L. Tzekov R.T. Efferent influences on the bioelectrical activity of the retina in primates.Doc Ophthalmol. 2017; 134: 57-73https://doi.org/10.1007/s10633-016-9567-5Crossref PubMed Scopus (12) Google Scholar]. Perhaps more likely altered processing in the thalamic or cortical processing of visual information. E.g. the lateral geniculate nucleus of the thalamus; allowing more input from the visual circuit to reach the visual cortex unhindered following ECT, given that a part of the visual circuit involves thalamic structures. Some evidence supports the involvement of diencephalic structures; e.g. the spike in heart rate associated with ECT [[7]Nagler J. Heart rate changes during electroconvulsive therapy.Ann Gen Psychiatr. 2013; 12: 19https://doi.org/10.1186/1744-859x-12-19Crossref PubMed Scopus (0) Google Scholar]. However, other visual information such as motion perception or other modalities such as hearing also passes through the thalamus and were not reported improved by the patient. Alternatively, the altered processing might occur in the primary visual cortex or higher-order visual processing sites and temporal regions. Though transcranial magnetic stimulation (TMS) and direct electrical stimulation of primary visual cortex (V1) and the adjacent area (V2) elicit phosphenes (a sensation of light) [[8]Salminen-Vaparanta N. Vanni S. Noreika V. Valiulis V. Móró L. Revonsuo A. Subjective characteristics of TMS-induced phosphenes originating in human V1 and V2.Cerebr Cortex. 2013; 24: 2751-2760https://doi.org/10.1093/cercor/bht131Crossref PubMed Scopus (25) Google Scholar], these phenomena did not appear in the patient nor are reported from others receiving ECT. The altered processing is, therefore, more likely at high order sites i.e. V4 and the inferotemporal cortex; the actual "colour centre" of the brain, this area is also located more anterior and closer to the ECT stimulation sites. Indeed, individuals with cerebral achromatopsia have lesions in V1, V2 and V4. Whether brain stimulation by ECT or TMS adds colour to their lives has not been studied. There is a current rival in the research on serotonergic psychedelics, e.g. LSD and psilocybin in the treatment of depression. During the psychedelic state, i.e. tripping, the subjective experience of colour is enhanced, and visual hallucinations occur and, yet, colour discrimination is reduced as tested on the Farnsworth Munsell hue test [[9]Hollister L.E. Hartman A.M. Mescaline, lysergic acid diethylamide and psilocybin: comparison of clinical syndromes, effects on color perception and biochemical measures.Compr Psychiatr. 1962; 3: 235-241https://doi.org/10.1016/s0010-440x(62)80024-8Crossref PubMed Google Scholar]. Interestingly, after the psychedelic state, an "afterglow" period with subjective wellbeing and heightened colour perception is reported. No studies have looked at colour perception during the psychedelic state, but there are anecdotal reports from colour-blind users reporting better colour perception on the online forums [[10]dk_trippy. Colorblindness and Psychedelics: an Experience with LSD, Mushrooms & AMT (exp 23143) Erowid.org. 2011Google Scholar]. The patient presented, in addition to increased colour vision, described increased wellbeing the afternoon and evening after ECT and may have been experiencing a similar afterglow as after psychedelic experiences. This suggests the antidepressant mechanism of ECT and psychedelics may share mechanisms of action. In conclusion, our case highlights that ECT can exert an objectively quantifiable effect on sensory perceptions. It is noteworthy that ECT, in this case, improved upon a neurological deficit utterly different from the affective stabilisation that we usually observe as the main effects of the treatment. How the patient's colour vision improved following ECT is not clear. All authors declare that they have no financial interests or any other conflict of interest with other people or organizations that could inappropriately influence this work.