The Hypothalamic-Pituitary Axis Is Vulnerable The hypothalamus and pituitary control thyroid function. The hypothalamus releases thyrotropin-releasing hormone (TRH), which signals the pituitary to release thyroid-stimulating hormone (TSH), which signals the thyroid gland to produce thyroid hormones T4 and T3. This signaling cascade requires intact hypothalamic and pituitary function. Concussion can disrupt the cascade at multiple points (Tanriverdi et al., 2015). Pituitary stalk vulnerability. The pituitary gland connects to the hypothalamus through the pituitary stalk, a narrow structure containing the blood vessels and nerve fibers that carry signals between the two regions. The stalk is anatomically vulnerable to shear forces during head injury. Damage to the stalk impairs the hormone signaling that thyroid function requires. The frequency is underrecognized. About 15-25% of patients develop measurable thyroid dysfunction after concussion. Up to 40% show some pituitary dysfunction in comprehensive testing. These numbers are higher than most providers recognize, which is why thyroid dysfunction often goes undiagnosed during PCS recovery. The Symptoms Often Get Attributed to PCS Alone Fatigue. Both PCS and hypothyroidism produce profound fatigue. When fatigue persists despite PCS treatment, untreated thyroid dysfunction may be contributing. The fatigue patterns differ subtly: PCS fatigue typically improves with rest, hypothyroid fatigue often does not. Weight gain. Hypothyroidism reduces basal metabolic rate by 10-20%. Combined with reduced PCS activity, weight gain becomes substantial. The metabolic component requires thyroid treatment, not just dietary changes. Brain fog. Thyroid hormone supports cognitive function. Hypothyroidism produces brain fog that overlaps with PCS cognitive symptoms. The cognitive component of hypothyroidism often responds dramatically to thyroid treatment when PCS-focused treatment alone has not. Cold intolerance. Reduced thyroid function reduces body temperature regulation. Patients feel cold when others are comfortable. The symptom is relatively specific to thyroid (not typical PCS). When present, it suggests thyroid involvement. Constipation. Slow thyroid function slows gut motility. New constipation after concussion suggests thyroid involvement, particularly if combined with other hypothyroid symptoms. Hair changes. Hair thinning, dry hair, and slower hair growth are classic hypothyroid signs. These changes typically appear 2-4 months after thyroid dysfunction develops. Dry skin. Reduced thyroid function reduces skin moisture. Skin becomes dry and rough. Combined with other hypothyroid signs, suggests testing. Mobility Support During Thyroid Treatment JME 155 Diaphragmatic breathing supports the autonomic regulation that thyroid function affects. The thyroid-autonomic interaction means breathing practice supports both systems simultaneously. 10 breaths every 60-90 minutes during active treatment. The autonomic support accelerates the symptomatic response to thyroid treatment. JME 14 Chin tucks address the cervical contribution to symptoms that compound thyroid effects. Reducing cervicogenic headache reveals the underlying thyroid contribution more clearly. 10 repetitions with 5-second holds. JME 1 Cervical rotation maintains the function needed for daily activity tolerance. As thyroid treatment restores energy, increased activity becomes possible. Maintaining cervical mobility supports the return to activity. 10 repetitions each direction. JME 150 Thoracic rotation supports breathing capacity that energy management requires. Thyroid recovery and energy return depend on adequate oxygenation. 8 repetitions per direction. Start your 3-day free trial for thyroid-recovery mobility programming. Testing the Thyroid Properly Standard TSH testing often misses post-concussion thyroid dysfunction. The pituitary damage of concussion can produce normal or low TSH despite low thyroid hormone levels (central hypothyroidism). The standard testing pattern fails to detect this pattern. More comprehensive testing is required. Request the comprehensive thyroid panel: TSH (with normal pituitary, indicates thyroid function) Free T4 (the storage form of thyroid hormone) Free T3 (the active form of thyroid hormone) Reverse T3 (indicator of T3 utilization) Thyroid antibodies (TPO and TgAb, to detect autoimmune thyroid disease) The patterns to look for: Primary hypothyroidism: High TSH, low free T4. Treatable with levothyroxine. Subclinical hypothyroidism: Mildly elevated TSH, normal free T4. May benefit from treatment if symptomatic. Central hypothyroidism: Low or normal TSH, low free T4. Indicates pituitary involvement. Endocrinology referral appropriate. Low T3 syndrome: Normal TSH and free T4, low free T3, possibly high reverse T3. Reflects T3 utilization problem. Treatment is controversial but T3 supplementation may help symptoms. Testing timing matters. Initial testing 6-8 weeks after concussion identifies early dysfunction. Repeat testing at 3-6 months catches dysfunction that develops later. Some patients develop thyroid dysfunction months after the original injury. Daily Movement Routine JME 3 Lateral cervical flexion daily supports the upper body mobility that thyroid recovery enables. As energy returns with treatment, increased daily activity becomes possible. 8 repetitions per side with 15-second holds. JME 42 Shoulder circles maintain upper-body mobility through the thyroid treatment response period. Treatment effects develop over 6-8 weeks, requiring maintained mobility throughout. 10 repetitions each direction. JME 15 Cervical extension supports posture and cerebral blood flow. The combined effect supports the thyroid treatment response. 8 repetitions. JME 151 Lateral side bends with breathing combine multiple supports during thyroid treatment. The efficiency makes this valuable during the energy-limited early treatment phase. 8 repetitions per side. Support thyroid recovery with simplmobility's mobility programming. Treatment Considerations Levothyroxine is the standard treatment for primary hypothyroidism. Daily morning dose, taken on empty stomach 30-60 minutes before food and other medications. The dose is adjusted based on TSH and free T4 monitoring every 6-8 weeks until stable. Some patients benefit from T3 or combination therapy. A subset of patients do not feel well on levothyroxine alone. Adding T3 (liothyronine) or using natural desiccated thyroid that contains both T3 and T4 helps some patients. Discuss with your provider if symptoms persist on T4-only treatment. Central hypothyroidism requires endocrinology. If testing suggests pituitary involvement, endocrinology consultation is appropriate. The treatment monitoring differs (free T4 rather than TSH) and other pituitary hormones may also need evaluation. Most patients see improvement in 6-8 weeks. Once on appropriate thyroid treatment, symptom improvement develops gradually over 6-8 weeks. Energy improves first, then cognitive function, then weight changes, then hair and skin changes (which take longer). Should I request thyroid testing if my provider has not ordered it? Yes. Comprehensive thyroid testing is appropriate for any PCS patient with persistent symptoms beyond 8-12 weeks. Specifically request the full panel (not just TSH). If your provider declines, request the testing through direct-to-consumer lab services or ask for an endocrinology referral. Will my thyroid function recover or do I need lifelong treatment? It depends on the type and severity. Some patients recover thyroid function as the pituitary heals, allowing eventual medication discontinuation. Others have persistent dysfunction requiring lifelong treatment. The pattern becomes clear with serial testing over 6-12 months. Can low-dose thyroid treatment help even if my numbers are normal? The question is debated. Most endocrinologists do not treat patients with normal lab values. Some functional medicine providers offer treatment based on symptoms. The decision involves individual risk-benefit assessment. The autonomic and cervical interventions of PCS often resolve symptoms attributed to subclinical thyroid issues, making treatment unnecessary. References Tanriverdi, F., et al. (2015). Pituitary dysfunction after traumatic brain injury. Endocrine Reviews, 36(3), 305-342. PubMed Patricios, J. S., et al. (2023). Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport, Amsterdam, October 2022. British Journal of Sports Medicine, 57(11), 695-711. PubMed