Faculty Development Case of the Month: February 2022

Clinical Cases from Emory Division of Hospital Medicine Annual Clinical Vignette Conference
Seeing is “B-elieving”: Progressive vision loss in an international traveler

Submitted by:
Ketino Kobaidze, MD, PhD, SFHM, FACP
Associate Professor of Medicine and Distinguished Physician
Division of Hospital Medicine
Emory Department of Medicine

Noble Maleque, MD, FHM, FACP
Assistant Professor of Medicine and Distinguished Physician
Division of Hospital Medicine
Emory Department of Medicine

Edited by Yelena Burklin, MD, FHM, FACP

CASE

A 31-year-old previously healthy practicing physician from West Africa was sent from an ophthalmology clinic for progressive vision loss over four months. He has traveled between West Africa, Israel, and the United States over the past year. He reported not eating meat but denied special dieting. Upon arrival in the United States, he experienced headaches, dizziness, and a sudden decrease in bilateral vision with a significant decrease in color saturation, followed by “flashes.” The patient was admitted to a local hospital in New York city with a negative workup for Neuromyelitis optica (NMO), syphilis, Lyme disease, and tuberculosis. Empirical steroid treatment was ineffective. Repeated ophthalmology evaluation over the next several months demonstrated decreased visual acuity: 20/125 OD, 20/150 OS with color desaturation and pallor to temporal aspect bilateral discs. Repeat serology for NMO was negative. Vitamin A level was within normal limits. Magnetic Resonance Imaging of the brain and orbits at that time revealed a new enhancement of bilateral nerve sheaths.

Patient was subsequently admitted to Emory University Hospital Midtown (EUHM) for further evaluation including lumbar puncture and to initiate high-dose steroids. He confirmed observing a vegetarian diet without any tobacco or alcohol use. His vital signs upon admission were within normal limits, and a focused physical examination (not including the aforementioned ophthalmologic examination) revealed no abnormalities. The Body Mass Index was 24 kg/m².

As a part of the comprehensive evaluation and while waiting for the results of the requested vitamin levels, in the setting of international travel and reported dietary restriction, a stool specimen for ova and parasites was obtained and revealed the presence of an intestinal protozoa (Blastocystis hominis).

What is your diagnosis?

FINAL DIAGNOSIS

Nutritional optic neuropathy due to multivitamin deficiency in the setting of intestinal protozoan infection contributing to malabsorption.

Hospitalization course:

Work up for possible etiology of optic neuropathy demonstrated multivitamin deficiency (Table 1) likely from deprived nutrition and poor gastrointestinal absorption from the presence of intestinal parasitic disease. His hospital course was uncomplicated: steroid treatment was stopped, and the parenteral vitamin B12 was initiated along with the replacement of vitamin B9 and a course of metronidazole to treat Blastocystis hominis infection.

Disease trajectory:

Eight months later, his vision has improved to the point where he elected to stop vitamin B12 and folic acid supplementation. He successfully continued to pursue a master’s degree in public health.

Table 1. Laboratory findings demonstrated the following:

Laboratory Values	Prior data	EUHM results	Reference values
Vitamin A	Decreased Data unavailable	0.75	0.3 – 1.2 mg/L
Vitamin B12	210	163	180 – 194 pcg/ml
Vitamin B9 (folate)	9	4.5	>5.9 ng/ml
Vitamin B6	33.8		20 – 125 nmol/L
Vitamin D	Unknown	low
AB against Intrinsic factor	Negative	Negative	Negative
CSF studies	Unknown	Unremarkable
NMO/AQP4 IgG AB	Negative	Negative	Negative
Syphilis IgM &IgG	Negative	Negative	Negative
MCV, peripheral blood	97.6	98	< 92fl HI
ACE level	Unknown	1.2	0-2.5 unit/L
ENA screen with reflux	Unknown	Negative	Negative
Fecal O&P	Not checked	Blastocystis hominis

DISCUSSION

Optic neuropathy from nutrition deficiency is rare in the USA, hence it can be easily missed. Our patient’s pre-hospital workup detected vitamin B12 and folate in low-normal levels but repeated testing confirmed profound deficiency from poor PO intake and malabsorption in the presence of the intestinal parasite. Blastocystis hominis is a common gastrointestinal parasite with high prevalence in resource-limited countries. While its pathogenicity is debatable, it is often found in association with other true pathogens requiring further examination. Nutritional optic neuropathies result from mitochondrial damage. The deficiency of vitamins B1, B9, B12, and minerals (copper) disturbs the mitochondrial oxidative phosphorylation process; accumulation of free radical products leads to Adenosine triphosphate (ATP) depletion and cell function failure. Also, axon demyelination and oxidative stress occur from the lack of the antioxidant properties of vitamins group B. Clinicians should conduct a thorough nutritional assessment for patients with sudden unexplained vision impairment. Treatment with the appropriate supplement may prevent further vision loss and complete recovery in the proper context.

CITATIONS

• Boeke CE, et al. Intestinal protozoan infections in relation to nutritional status and gastrointestinal morbidity in Colombian school children. J Trop Pediatr. 2010 Oct;56(5):299-306. doi: 10.1093/tropej/fmp136
• Dogruman-AI F, et al. A possible link between subtype 2 and asymptomatic infections of Blastocystishominis. Parasitol Res. 2008 Aug;103(3):685-9. doi: 10.1007/s00436-008-1031-3