MG presents mostly with fluctuating fatigue and weakness of a specific muscle group. Because of confusion with signs of the ageing process or comorbidities due to ageing, a large section of the older population are either underdiagnosed or misdiagnosed as MG [
7]. Several laboratory investigations and clinical expertise are required for a proper diagnosis of MG. In the context of resource-deprived nations like Nepal, several of the investigations are not readily available. Lack of health care or subsidy adds further difficulties in getting investigations done due to extra expenses. This adds fuels to the diagnostic dilemma for health care professionals. MG is still mainly a clinically diagnosed disease characterized mostly by fluctuating symptoms. However, investigations are needed to cement the diagnosis. Investigations are laboratory testing, electrophysiological testing, and pharmacological testing. The pharmacological testing is done with edrophonium chloride or neostigmine or pyridostigmine. Electrophysiological testing such as electromyographic testing is done with repetitive nerve stimulation (RNS) and/or single-fiber electromyography (SFEMG); laboratory tests are mainly the serologic value of AchR or muscle-specific tyrosine kinase (MUSK) antibodies, and other tests such as CPK-Nac to rule out other possible causes.
The fatigability of the peripheral skeletal muscle is the hallmark of the disease and it can be absent in bulbar forms [
8]. The bulbar form of MG would present as dysarthria, chewing fatigue, and/or dysphasia [
9]. A case of a voice fatigue was also reported in one of the case reports [
10]. However, in focal bulbar weakness, MND is suspected first [
11]. Similarly, hypophonia without obvious dysarthria is more commonly seen in PD [
12] with slow but progressive speech intensity decay [
12]. As stated earlier, few case reports have been published regarding bulbar weakness like dysphonia [
13,
14] in MG. They argued that there is palatal and/or laryngeal weakness in MG [
15] and it can be a presenting symptom in late-onset MG [
14]. We present a relatively rarer presentation of MG. Our case had a sudden onset and fluctuating hypophonia without obvious palatal weakness or nasal tone. This is different from the various cases that have been reported previously. Previous case reports discussed other bulbar features such as dysphasia, aspirations, vocal fatigability, or nasal tones [
13,
14]. Our case had apparently none of these or any other problem other than hypophonia. For hypophonia, she had multiple other non-neurological consultations including ENT consultations without any improvement. Due to unavailability of electroglottography (EGG) and speech acoustics, she was evaluated by the ENT department for palatal weakness and they reported it to be as normal. Hence, without these standard facilities, we rely on physical examinations, clinical experience, and available laboratory tests to diagnose the disease. With the symptoms, we had a strong suspicion of MG. The QMG test is easy to administer and correlates well with activities of daily living [
16]. SFEMG is more specific in MG [
17] but technically more demanding and is also beyond our reach in Nepal, at present. Positive AchR ab confirms MG in a patient with appropriate symptoms and clinical findings [
18,
19]. The laboratory report of our patient revealed high AchR (1.11 ng/ml). Of patients with thymoma, 20–25% have MG and 10–20% of patients with MG have thymoma [
20,
21]. Patients with MG with thymoma are older and symptoms are more severe. Plain and enhanced CT scans of our patient’s chest and neck showed the presence of thymoma. Approximately 70% of cases of thymoma in patients with MG have titin and ryanodine receptor (RyR) antibodies. Unfortunately, again due to the limitation of our resources, a MUSK, RyR, or titin receptor antibodies assay could not be performed in our patient. Pyridostigmine is considered the first line of therapy. Our patient responded well to orally administered pyridostigmine and the drug treatment led to a rapid improvement in her speech quality and vocal symptoms. She was maintained on pyridostigmine and subsequently sent to the thoracic surgery department for surgical management of the thymoma. An informed written consent was obtained to publish this case report.