Endocrinology Services
for Acquired Brain Injury
Specialist hormonal and metabolic care for post-ABI endocrine disruption — including Well Man Clinic (TRT) and Well Woman Clinic (HRT).
Hormonal disruption following Acquired Brain Injury is one of the most significant — and most consistently underdiagnosed — sequelae of brain injury. The hypothalamus and pituitary gland are among the most vulnerable structures in both traumatic brain injury (TBI) and hypoxic/anoxic brain injury. Disruption to the hypothalamic-pituitary axis can produce a cascade of endocrine disorders that profoundly affect mood, cognitive function, energy levels, libido, sleep, bone density, metabolic function and physical recovery trajectory.
At Nexus ABI, our endocrinology service provides structured assessment and evidence-based management of post-ABI hormonal conditions, following current NICE guidelines, British Society for Sexual Medicine (BSSM) guidance, Society for Endocrinology recommendations and the British Menopause Society (BMS) position statements.
Common ABI-related endocrine conditions:
Hypothalamic-pituitary conditions
- Hypopituitarism — growth hormone deficiency (most common post-TBI endocrinopathy)
- ACTH deficiency and secondary adrenal insufficiency
- Central hypothyroidism (TSH deficiency)
- Central hypogonadism — low testosterone in males, ovarian dysfunction in females
- Diabetes insipidus (post-TBI or post-neurosurgical)
- Prolactinoma or hyperprolactinaemia secondary to pituitary stalk disruption
- Syndrome of inappropriate antidiuretic hormone (SIADH)
Metabolic and functional consequences
- Metabolic syndrome driven by neuroendocrine and hypothalamic changes
- Unexplained fatigue, cognitive impairment and mood disorder with hormonal aetiology
- Sexual dysfunction — erectile dysfunction, low libido, anorgasmia — in both sexes
- Reduced bone mineral density and increased fracture risk
- Abnormal body composition — loss of muscle mass, increased central adiposity
- Impaired cardiovascular risk profile secondary to endocrine disruption
- Delayed recovery trajectory that does not respond to rehabilitation alone
Diagnostic approach
Standard hormonal panel includes: Total testosterone, calculated free testosterone, LH, FSH, oestradiol, SHBG, prolactin, morning cortisol (fasting), ACTH, IGF-1, TSH, free T4, free T3, HbA1c, fasting glucose, full lipid profile, CRP, FBC, renal and liver function, vitamin D, vitamin B12.
Additional dynamic tests (e.g. short Synacthen test, insulin tolerance test) are arranged via our specialist liaison pathways where indicated.
Well Man Clinic — Testosterone Replacement Therapy (TRT)
Testosterone deficiency (hypogonadism) is found in 20–40% of male TBI survivors in research cohorts, yet remains significantly under-tested in clinical practice. The consequences — fatigue, cognitive impairment, mood instability, loss of muscle mass, sexual dysfunction and reduced bone density — are frequently attributed to the brain injury itself, delaying appropriate hormonal treatment. Our TRT service follows the BSSM evidence-based guidelines for testosterone deficiency in adult men.
Eligibility assessment
- Symptomatic hypogonadism confirmed by validated symptom questionnaire (ADAM or AMS scale)
- Two fasting morning total testosterone measurements below 12 nmol/L (or free testosterone < 0.225 nmol/L)
- Exclusion of reversible secondary causes (illness, medication, sleep apnoea, obesity, psychological)
- Baseline PSA (men over 40 or risk group), digital rectal examination where indicated
- Full cardiovascular risk assessment — BP, BMI, lipids, HbA1c, QRISK3 calculation
- Haematocrit (packed cell volume) and full blood count at baseline
- Renal and liver function baseline
Treatment options (BSSM-aligned)
- Transdermal gel (preferred for dose flexibility and physiological delivery): applied daily to clean dry skin — shoulder/inner arm
- Intramuscular injection (Sustanon 250: every 3 weeks, or Nebido/testosterone undecanoate: every 10–14 weeks): administered by our nursing team in-home
- Dose titrated to maintain total testosterone in the mid-normal range (15–30 nmol/L) per BSSM guidance
- Haematocrit monitored: treatment paused if PCV exceeds 54%
- PSA monitored 3-monthly for first year, then annually — treatment stopped if PSA rises > 1.4 ng/mL above baseline in 12 months
- Fertility: patients advised TRT suppresses spermatogenesis — documented discussion and consent required
Monitoring schedule (TRT)
- 3 months: total testosterone, haematocrit, PSA, LFTs, BP, weight, symptom review
- 6 months: full hormone panel, metabolic panel, haematocrit, cardiovascular review
- 12 months: full clinical review, bone density referral if indicated, DRE if PSA changes
- Ongoing: 6-monthly bloods, annual full review — all results shared with case manager
Absolute contraindications to TRT
- Active or suspected prostate or breast cancer
- Haematocrit > 54% (polycythaemia)
- Untreated severe obstructive sleep apnoea
- Uncontrolled congestive heart failure
- Desire to maintain or restore fertility in the short term (refer to reproductive medicine)
Well Woman Clinic — HRT & Female Hormonal Health
Women with Acquired Brain Injury face a substantially increased risk of premature ovarian insufficiency (POI), menopause occurring earlier than expected, and significantly worsened menopausal symptoms. Hormonal changes interact powerfully with neurological injury — disrupting sleep, amplifying mood instability, worsening cognitive symptoms and accelerating bone loss. Our Well Woman Clinic provides structured assessment and management following NICE guideline NG23 (Menopause, 2015, updated 2019) and British Menopause Society guidance.
Assessment & indications
- Premature ovarian insufficiency (POI): FSH > 40 IU/L on two measurements 4–6 weeks apart, in women under 40 — NICE recommends offering HRT promptly
- Perimenopause: irregular cycles + vasomotor or psychological symptoms — clinical diagnosis, FSH not required
- Menopause: 12 months amenorrhoea + symptoms — clinical diagnosis
- Baseline bloods: FSH, LH, oestradiol, testosterone, SHBG, thyroid function, prolactin, full metabolic panel, bone markers
- Personal and family history: cardiovascular disease, breast cancer, VTE, uterine or ovarian cancer — full risk stratification
- BMI, blood pressure, breast examination (or referral for mammography if due)
Treatment options (NICE NG23 & BMS-aligned)
- Oestrogen: transdermal patch or gel — preferred over oral (lower VTE risk; no first-pass hepatic effect — NICE recommendation)
- Progestogen: micronised progesterone (body-identical, e.g. Utrogestan) — preferred per NICE/BMS for lower breast cancer signal
- Combined continuous or sequential regimens based on cycle status and uterine presence
- Testosterone (off-label, per BSSM guidance for females): for hypoactive sexual desire disorder (HSDD) or persistent fatigue — typically Testogel at low dose, or compounded cream
- Vaginal oestrogen: for urogenital atrophy — safe to use long-term regardless of systemic HRT status
- Local oestrogen and DHEA options for patients where systemic HRT is not appropriate
Monitoring schedule (HRT)
- 3 months: symptom response, side effects, BP, weight, bleeding pattern review
- 6 months: oestradiol level if using patches (target 200–400 pmol/L); testosterone level if prescribed
- 12 months: full hormonal panel, lipid profile, BP, weight, mammographic recall coordination
- Ongoing: annual review, bone density DEXA scan at 2 years for POI patients, shared-care letter to GP updated annually
Contraindications to HRT
- Current or suspected breast cancer or oestrogen-sensitive malignancy
- Undiagnosed vaginal bleeding
- Active or recent VTE — seek haematology advice on thrombophilia before prescribing
- Uncontrolled hypertension — stabilise before initiating
- Active liver disease with abnormal LFTs — consider alternative routes
Frequently Asked Questions
Our FAQ section is here to answer the most common questions about this service and help you feel fully informed before getting started. If you don’t see the answer you’re looking for, please don’t hesitate to get in touch—our team is always happy to help and provide clarity where needed.
Why is hormonal disruption so common after an Acquired Brain Injury?
The hypothalamus and pituitary gland — the master regulators of the body’s hormonal system — are among the most structurally vulnerable parts of the brain in both traumatic and hypoxic injury. Even relatively minor TBI can disrupt the hypothalamic-pituitary axis, leading to deficiencies in one or more hormones including growth hormone, testosterone, cortisol, thyroid hormones and antidiuretic hormone. Research suggests that up to 30–40% of TBI survivors have clinically significant pituitary dysfunction, yet this remains substantially under-tested and under-treated in routine clinical practice.
How do I know if my patient's symptoms are hormonal rather than purely neurological?
Many of the hallmark symptoms of pituitary dysfunction — persistent fatigue, cognitive impairment, mood instability, low libido, loss of muscle mass, weight gain and poor sleep — overlap significantly with the neurological sequelae of brain injury. The only way to reliably distinguish or confirm a hormonal contribution is through structured blood testing. Our diagnostic assessment includes a comprehensive hormonal panel and specialist clinical interpretation to identify treatable endocrine causes of ongoing symptoms.
What does the initial endocrinology assessment involve?
The initial assessment begins with a detailed clinical consultation covering symptom history, medical history and current medication review. This is followed by a comprehensive fasting hormonal blood panel collected in-home by our phlebotomy team. The panel includes testosterone (total and calculated free), LH, FSH, oestradiol, SHBG, prolactin, morning cortisol, ACTH, IGF-1, TSH, free T4, free T3, HbA1c, full lipid profile, vitamin D, renal and liver function, and full blood count. Results are interpreted by our specialist clinician and a treatment plan produced within a written report.
What is TRT and who is eligible following a brain injury?
Testosterone Replacement Therapy (TRT) is the treatment of testosterone deficiency (hypogonadism) — a significantly underdiagnosed condition in male ABI survivors. Eligibility is confirmed where: (1) two fasting morning testosterone measurements fall below 12 nmol/L, (2) the patient has symptomatic hypogonadism confirmed on validated questionnaire (ADAM or AMS scale), and (3) reversible secondary causes have been excluded. Treatment is initiated and monitored in line with current British Society for Sexual Medicine (BSSM) guidelines.
What forms of TRT does Nexus ABI prescribe?
We prescribe and manage the full range of TRT delivery methods available in the UK: daily transdermal gel (applied to shoulder or inner arm), long-acting intramuscular injection (either 3-weekly Sustanon 250 or 10–14-weekly testosterone undecanoate), and we can advise on subcutaneous pellet options where clinically appropriate. The preferred method is decided in collaboration with the patient (or their Best Interests decision-maker) based on clinical suitability, carer capacity and practical considerations. Intramuscular injections are administered by our in-home nursing team.
How is TRT monitored and what are the risks?
TRT monitoring follows the BSSM evidence-based framework. Bloods are checked at 3 months (testosterone level, haematocrit, PSA, liver function) and 6 months (full hormonal and metabolic panel), then 6-monthly on a stable dose. The principal risks managed are polycythaemia (elevated haematocrit — treatment paused if packed cell volume exceeds 54%), PSA rise (monitored for prostate health — particularly in men over 40), and cardiovascular risk factors. TRT is not prescribed where there is active prostate or breast cancer, untreated severe obstructive sleep apnoea, or a desire to preserve fertility in the short term.
Can female ABI patients also have hormonal treatment?
Yes. Our Well Woman Clinic provides specialist hormonal assessment and HRT for women affected by premature ovarian insufficiency (POI), perimenopause and menopause following brain injury. Women with ABI are at elevated risk of POI and tend to experience worsened menopausal symptoms due to the interaction between hormonal changes and neurological injury. HRT is prescribed following the NICE NG23 and British Menopause Society guidelines, with a preference for transdermal oestrogen and body-identical micronised progesterone. Testosterone therapy for low libido or fatigue in women is also available where clinically indicated, following BSSM guidance.
Can hormonal treatment improve cognitive function after brain injury?
There is a growing body of evidence that testosterone deficiency and oestrogen deficiency each have negative effects on cognitive function, memory and processing speed — and that restoring hormonal levels to the normal range can contribute to improvements in these domains. This is particularly relevant in ABI patients where cognitive impairment is already present and where any reversible contributing factor should be addressed. We do not claim that hormonal treatment will reverse neurological injury, but where hormonal deficiency is identified, treating it is an evidence-based component of optimising the patient’s functional recovery.
How long does hormonal treatment take to show a benefit?
Most patients begin to notice improvements in energy, mood and libido within 4–8 weeks of initiating treatment, with more significant changes in body composition, cognitive clarity and sexual function typically apparent at the 3–6 month mark. Full therapeutic benefit — particularly for bone density and metabolic markers — may take 12–24 months. We review progress formally at 3 months and adjust the treatment plan based on both symptom response and blood results.
Can hormonal treatment be funded through a personal injury settlement?
Yes. Endocrinology assessment, ongoing monitoring and pharmacological treatment are all eligible for funding via personal injury settlement budgets managed by case managers or financial deputies. We provide fully itemised clinical invoices with clear treatment justification suitable for Court of Protection review and deputyship audit. A detailed fee schedule is available on our Fees & Funding page.