Subtle Speech and Cognitive Deficits in a Woman With Hypothyroidism

February 7, 2019

This middle-aged woman attributes recent changes in her thinking and speech patterns to long-standing hypothyroidism. Do you concur?

THE CASE

A 45-year-old woman seeks a medical evaluation because she is worried that her thinking and speech patterns have been slower than usual for the past 6 months.

History

The patient has long-standing hypothyroidism and takes thyroid replacement medication. She has been approximately 30 lb overweight since the birth of her only child 14 years earlier, at about the time hypothyroidism was diagnosed.

Her husband, who has accompanied her, says that he has not noticed any changes in her speech pattern. He explains that her speech has always been deliberate and that she was methodical and careful even before hypothyroidism was diagnosed. Yet, the patient says that it takes her longer to get things done and that she has been making mistakes in paying her bills and in performing simple tasks at work, despite the fact that she has had the same job, which is fairly routine, for 10 years.

In response to these problems, she decided to increase the dose of her thyroid replacement medication about a month earlier. She did not notice any improvement in her symptoms, and she began to experience palpitations. She checked her blood pressure with a self-monitoring device and found that it was 160/100 mm Hg, which is elevated in comparison to her baseline value.

Physical examination

The patient is alert, oriented, and cooperative. Her skin and eyes appear normal. Her speech pattern is slow, and her speech is oddly deliberate. She is able to count to 20 accurately but does so very slowly. She is also accurate but very slow in counting backward from 20. Her immediate and delayed recall of three objects is intact.

On neurological examination, her strength is normal in both lower extremities and in the left upper extremity. She has 4/5 strength of her right upper extremity. Her reflexes are normal with the exception of mild hyperreflexia of the right upper extremity. Her light touch, pinprick, vibration, and position sense are normal in all four extremities. Her coordination and gait are normal without any asymmetry.

She is tachycardic, with a heart rate of 175 beats per minute and a normal rhythm. Pulses are normal, and blood pressure is 170/110 mm Hg. Respiration sounds are normal, as are the result of an abdominal examination.

Diagnostic tests

The patient’s thyroid-stimulating hormone level is low.

A brain MRI scan with contrast is ordered.

What do you suspect is the cause of this woman’s neurological symptoms?

See next page for MRI findings and the diagnosis. >

DIAGNOSIS: MENINGIOMA

The brain MRI scan with contrast showed a 3-cm meningioma above the left temporal lobe, without invasion into the brain tissue. No other tumors or abnormalities were seen.

The patient was asked to lower the dose of her thyroid replacement medication to her usual regimen, and her tachycardia and high blood pressure resolved within a week.

This patient’s meningioma was the likely cause of her speech disturbance, which was described as resembling a mild Broca’s aphasia. Her extremely slow, deliberate, and careful speech may have been an attempt to compensate for the mild deficit caused by the tumor. It was not substantially different from her baseline speaking pattern, which made it difficult for her husband to recognize. It was her mistakes at home and at work (which were also subtle) that prompted her to seek medical attention.

Outcome of this case

After surgical removal of the benign tumor, she had no postoperative complications, and her speech and cognitive function returned to baseline within 1 month. Her right upper extremity weakness resolved, and her right upper extremity reflexes remained brisk at the 1-month follow-up examination.

Discussion

A meningioma can arise from the meninges that surround the brain or the spinal cord. The symptoms can vary and may include headaches, fatigue, vision problems, personality changes, and motor weakness.1 Aphasia is not among the most common symptoms of a meningioma, but, depending on the location of the tumor and/or any surrounding edema, almost any neurological symptom can occur.

In this instance, the patient had a small meningioma that was described as benign in appearance. While most meningiomas are benign, it is estimated that between 10% and 20% may recur or may be malignant, potentially invading brain tissue.2

In most situations, complete removal of the tumor is the best treatment. A separate biopsy procedure is usually not recommended because that would entail more than one procedure. Nevertheless, microscopic examination of the resected tumor tissue is useful for determining whether the tumor is benign or malignant. Often, the appearance of the tumor on imaging and during surgery can identify malignancy.

Some patients may experience bleeding, swelling, or edema postoperatively, and close observation is necessary for identification and management of these complications. Larger tumors are more likely to be associated with more severe symptoms as well as a higher likelihood of postoperative complications.

Take-home points

• A meningioma can produce subtle neurological problems. Exaggeration of baseline idiosyncrasies (such as slow speech) can make it difficult for family members to notice vague or generalized changes in neurological function.

• A biopsy is typically not necessary. Imaging is often diagnostic, and surgery for complete removal of the brain tumor is the treatment of choice whenever possible.

• Because thyroid disease causes so many symptoms, patients often believe that new symptoms are related to thyroid disease. While this is often the case, a wider differential must be considered, even if the symptoms could be explained by thyroid disease.

References:

1. Wu A, Garcia MA, Magill ST, et al. Presenting symptoms and prognostic factors for symptomatic outcomes following resection of meningioma. World Neurosurg. 2018;111:e149-e159. doi: 10.1016/j.wneu.2017.12.012. Epub 2017 Dec 14.

2. Champeaux C, Jecko V, Houston D, et al. Malignant meningioma: an international multicentre retrospective study. Neurosurgery. 2018 Dec 19. doi: 10.1093/neuros/nyy610. [Epub ahead of print]