Psychiatric manifestations of MSA
There are a few case reports of depression identified early in patients who were later given a diagnosis of MSA.8
Depression. In a study by Benrud-Larson et al9 (N = 99), 49% of patients who had MSA reported moderate or severe depression, as indicated by a score of ≥17 on the Beck Depression Inventory (BDI); 80% reported at least mild depression (BDI ≥10, mean 17.0, standard deviation, 8.7).
In a similar study, by Balas et al,10 depression was reported as a common symptom and was statistically significant in MSA-P patients compared with controls (P = .013).
Anxiety, another symptom that was reported by Mr. M, is another psychiatric manifestation described by Balas et al10 and Chang et al.11 Balas et al10 noted that MSA-C and MSA-P patients had significantly more state anxiety (P = .009 and P = .022, respectively) compared with controls, although Chang et al11 noted higher anxiety scores in MSA-C patients compared with controls and MSA-P patients (P < .01).
Balas et al10 hypothesized that anxiety and depression contribute to cognitive decline; their study showed that MSA-C patients had difficulty learning new verbal information (P < .022) and controlling attention (P < .023). Mr. M exhibited some of these cognitive difficulties in his reports of losing track of conversations, forgetting the topic of a conversation when speaking, trouble focusing, and difficulty concentrating when driving.
Mr. M had depression and anxiety well before onset of autonomic dysfunction (orthostatic hypotension and erectile dysfunction), which eventually led to an MSA diagnosis. Psychiatrists should understand additional manifestations of MSA so that they can use psychiatric symptoms to identify these conditions in their patients. One of the most well-known and early manifestations of MSA is autonomic dysfunction; among men, another early sign is erectile dysfunction.6 Our patient also exhibited other less well-known symptoms linked to MSA and autonomic dysregulation, including RBD and ocular symptoms (iridocyclitis, glaucoma, decreased visual acuity).
Rapid eye-movement behavior disorder. Psychiatrists should consider screening for RBD during assessment of sleep problems. Identifying RBD is important because early studies have shown a strong association between RBD and development of a neurodegenerative disorder. Mr. M’s clinicians did not consider RBD, although his symptoms of sleepwalking and falling asleep while driving suggest a possible diagnosis. Also, considering this diagnosis would aid in diagnosing a synucleinopathy disorder because a higher incidence of RBD was noted in patients who developed synucleinopathy disorders (eg, Parkinson’s disease [PD] and dementia with Lewy bodies [DLB]) compared with patients who developed non-synucleinopathies (eg, frontotemporal dementia, corticobasal degeneration, progressive supranuclear palsy, mild cognitive impairment, primary progressive aphasia, and posterior cortical atrophy) or tauopathies (eg, Alzheimer’s disease).12
Zanigni et al13 reported similar findings in a later study that classified patients with RBD as having idiopathic RBD (IRBD) or RBD secondary to an underlying neurodegenerative disorder, particularly an α-synucleinopathy: PD, MSA, and DLB. Most IRBD patients developed 1 of the above mentioned neurodegenerative disorders as long as 10 years after a diagnosis of RBD.
In a study by Iranzo et al,14 patients with MSA were noted to have more severe RBD compared with PD patients. Severity is illustrated by greater periodic leg movements during sleep (P = .001), less total sleep time (P = .023), longer sleep onset latency (P = .023), and a higher percentage of REM sleep without atonia (RSWA, P = .001). McCarter et al15 also noted a higher incidence of RSWA in patients with MSA.
Patients with MSA might therefore be more likely to exhibit difficulty initiating and maintaining sleep and as having RSWA years before the MSA diagnosis.
Several psychotropics (eg, first-generation antipsychotics, tricyclic antidepressants, lithium, benzodiazepines, carbamazepine, topiramate, and selective serotonin reuptake inhibitors) can cause adverse ocular effects, such as closed-angle glaucoma in predisposed persons and retinopathy.16 Therefore, it is important for psychiatrists to ask about ocular symptoms because they might be an early sign of autonomic dysfunction.
Posner and Schlossman17 theorized a causal relationship between autonomic dysfunction and ocular diseases after studying a group of patients who had intermittent unilateral attacks of iridocyclitis and glaucoma (now known as Posner-Schlossman syndrome). They hypothesized that a central cause in the hypothalamus, combined with underlying autonomic dysregulation, could cause the intermittent attacks.
Gherghel et al18 noted a significant difference in ocular blood flow and blood pressure in patients with primary open-angle glaucoma (POAG) compared with controls. Patients with POAG did not show an increase in blood pressure or ocular blood flow when challenged by cold water, which should have increased their sympathetic activity. Gherghel et al18 concluded that this indicated possible systemic autonomic dysfunction in patients with POAG. In a study by Fischer et al,19 MSA patients also were noted to have significant loss of nasal retinal nerve fiber layer thickness vs controls (P < .05), leading to decreased peripheral vision sensitivity.