Stiff Person Syndrome; thoracic and lumbar paravertebral muscle spasms/upper back spasms; right hand pain; dysarthria; right hand/arm spasticity; This case was reported in a literature article and described the occurrence of stiff person syndrome in a 16-year-old female patient who received HPV 16-18 (HPV vaccine) for prophylaxis.  Concurrent medical conditions included autoimmune thyroiditis.   On an unknown date, the patient received HPV vaccine. On an unknown date, 1 month after receiving HPV vaccine, the patient experienced stiff person syndrome (serious criteria GSK medically significant), spasms, pain in hand, dysarthria and spasticity. The subject was treated with dantrolene sodium (Dantrolene), levetiracetam, botulinum toxin type a (Botulinum Toxin), immunoglobulins nos (Intravenous Immunoglobulin), operations and procedures (Plasma Exchange), rituximab, benzodiazepine, nos (Benzodiazepines), baclofen, tizanidine and methocarbamol. On an unknown date, the outcome of the stiff person syndrome, spasms, pain in hand, dysarthria and spasticity were unknown.   It was unknown if the reporter considered the stiff person syndrome, spasms, pain in hand, dysarthria and spasticity to be related to HPV vaccine.  Additional details were provided as follows: This case was reported in a literature article and described the occurrence of Stiff Person Syndrome in a 16.9 years old female patient, who was vaccinated with unspecified Human Papillomavirus (HPV) vaccine (manufacturer unknown) for prophylaxis.  The patient was a part of the study that aimed was to characterize the spectrum of clinical features and examination findings in pediatric-onset stiff person syndrome. [In this study, medical records were reviewed for all patients treated for stiff person syndrome with symptom onset in childhood at a tertiary medical center between March 2001 and February 2019. Cases were included if they met clinical criteria for stiff person syndrome (SPS) based on an adapted Dalakas Criteria and if SPS symptom onset occurred before age 18 years]. The patient was woman. The patient had personal history of autoimmunity as autoimmune thyroiditis. The patient had no family History of autoimmunity. No information on patient's concurrent condition or concomitant medication was provided. On an unspecified date, 1 month before symptom onset, the patient received unspecified Human Papillomavirus (HPV) vaccine (administration route and site unspecified, dosage unknown; batch number not provided). On an unspecified date, between March 2001 and February 2019, an unknown period after the vaccination, the patient had initial presentation to center as upper back spasms; right hand pain. Time to diagnosis from symptom onset was 2.5 years. Exam findings at initial presentation to center was dysarthria; right hand/arm spasticity; thoracic and lumbar paravertebral muscle spasms; feet spasms. At the age of 19.4 years, the patient was diagnosed to Stiff Person Syndrome Phenotype as classic. Serum Anti-glutamate decarboxylase 65 (GAD65) antibody titers was 3183 IU/ml (normal less than or equal to 1 IU/ml). Serum anti-amphiphysin antibodies was negative. Serum Anti-Glycine receptor (GlyR) antibodies was negative. CSF white blood cell count was 1/uL (normal 6-7/uL). CSF Protein was 47 mg/dl (normal 15-60 mg/dL). More than 2 oligoclonal bands unique to CSF was unknown. CSF Anti-GAD65 antibody titers was 0.05 nmol/L (normal less than 0.02 nmol/L). Electromyography (EMG) was continuous muscle fiber activity and co-contraction of agonist and antagonist muscles (tibialis anterior and gastrocnemius muscles). Immunotherapy received or currently receiving was intravenous immunoglobulin, plasma exchange, rituximab. Relevant symptomatic treatments received or currently receiving was benzodiazepines, baclofen, dantrolene, tizanidine, methocarbamol, levetiracetam, and botulinum toxin. Modified Rankin Scale (mRS) score at Most Recent Visit was 4. Timed 25 foot walk test at most recent visit was wheel-chair bound. [Within the study period, 186 patients with SPS were seen. Fifteen patients (8%) had symptom onset in childhood, of whom 11 (73%) were female and 13 (87%). The median age of symptom onset was 14.8 years (range 8.4 to 16.9 years), and the median latency from symptom onset to diagnosis was 6.2 years (range 0.4 to 15.0 years). Nine individuals (60%) were not diagnosed until adulthood, despite symptom onset occurring during childhood. Twelve individuals met criteria for classic SPS and three for progressive encephalomyelitis with rigidity and myoclonus (PERM). Individuals had a median total of four of the 12 symptoms and examination findings assessed (range 2 to 8), and 13 individuals (87%) had three or more reported features. Of the 15 individuals who met inclusion criteria, 11 (73%) were female and 13 (87%). Median age at symptom onset was 14.8 years (range 8.4 to 16.9), and median latency from symptom onset to diagnosis was 6.2 years (range 0.4 to 15.0). Nine individuals (60%) were not diagnosed until adulthood. The most common presenting features were painful spasms (n = 12, 80%), hyper-reflexia (n = 11, 73%), axial rigidity (n = 9, 60%), lower extremity rigidity or spasticity (n = 8, 53%), gait abnormalities (n = 6, 40%), and hyperlordosis (n = 6, 40%). Other noted features included anxiety (n = 5, 33%), dysautonomia (n = 3, 20%), and cranial neuropathies (n = 3, 20%; e.g., ptosis, double vision, nystagmus, and eye movement abnormalities). Personal (n = 9, 60%) and family history (n = 9, 60%) of autoimmune conditions was common. Serum antiglutamate decarboxylase 65 antibodies were found in 13 individuals (87%). Nearly all individuals received immunotherapy (n = 14, 93%), symptomatic medications (n = 15, 100%), and non-pharmacologic therapies (n = 14, 93%). However, most had persistent physical limitations, particularly impaired walking (n = 7, 47%) and inability to carry out previous activities (n = 14, 93%). Eight individuals (53%) reported having possible triggering events within one to three months of symptom onset. These events included a preceding infection (Ehrlichia along with Lyme disease-related Bell's Palsy and mononucleosis in one individual each), vaccination against human papillomavirus (in two individuals), concussion (in one individual), head trauma related to a motor vehicle accident (in one individual), and stressful life event (parents' divorce and familial financial stress in one individual each). Personal history (n = 9, 60%) and first-degree relative family history (n = 9, 60%) of autoimmune disease were commonly seen. Thirteen individuals (87%) had positive serum anti-GAD65 antibody titers (median 3183 IU/mL, range 1.2 to 184,320 IU/mL; normal less than or equal to 1 IU/mL) at the time of first evaluation in center, three of whom were on immunotherapy for concurrent autoimmune disease at that time. No individual had detected anti-amphiphysin antibodies, one individual had anti-GlyR antibodies, and one individual had both anti-GAD65 and anti-GlyR antibodies. Seven individuals (64%) underwent lumbar punctures; three individuals (43%) had pleocytosis (6 to 17/mL), one individual (14%) demonstrated oligoclonal bands unique to the cerebrospinal fluid, and all three individuals who had cerebrospinal fluid anti-GAD65 antibody testing were positive (more than 0.02 nmol/L). Cerebrospinal fluid (CSF) oligoclonal band testing was either unknown or not performed (n = 2) or not present (n = 1) in the three individuals with detected CSF anti-GAD65 antibodies. All individuals had electromyography, and five individuals (36%) had abnormal results: continuous muscle fiber activity at rest, or cocontraction of agonist and antagonist muscles, or combination of these findings. Nearly all individuals received immunotherapy (n = 14, 93%), symptomatic medications (n = 15, 100%), and a variety of non-pharmacologic therapies (n = 14, 93%), reporting most favorable responses to a combination of interventions. At the most recent clinic visit mRS score, which assigns scores to motor disability from 0 (no symptoms) to 6 (dead), was assessed (median 12.2 years from symptom onset, range 1.03 to 27.6 years). Individual scores ranged from 1 to 4 with a median score of 3. An increased number of symptoms and neurological examination abnormalities was seen in individuals with higher mRS scores. None of the individuals with more than four symptoms and signs had an mRS score of less than 3. Three individuals (20%) were wheelchair-dependent, and two (13%) required walker or unilateral cane. T25FW test results were available for nine individuals]. The outcome of the event was not reported. The author commented, "In this study, we demonstrated a wide spectrum of both typical and less commonly seen features in individuals with pediatric onset SPS. Delay in diagnosis, whether secondary to unrecognized symptoms or limited knowledge of the disease by clinicians, appears to be common, as diagnosis is often delayed until adulthood, at which point disability accrual is frequently seen. Although SPS is a rare neurological disease, recognition and initiation of treatment is critical to addressing patients' symptoms and may enable improved outcomes and quality of life. Therefore such delays in diagnosis may be even more problematic in children with SPS, where functional impairment during a time of ongoing neurological and social development may have a profound impact on long term well-being and functionality. In our cohort, nearly two of three individuals did not receive a diagnosis of SPS until adulthood despite symptom onset in childhood, and median latency from symptom onset to diagnosis was more than six years. Although most children with SPS present with a similar clinical phenotype to adults with SPS, other clinical features were identified in our series. The most common presenting symptoms and examination findings were painful spasms, hyperreflexia, axial rigidity, and lower extremity rigidity and spasticity. Other features seen include gait abnormalities, hyperlordosis, dysautonomia, anxiety, and cranial neuropathies. The presence of such symptoms should therefore not discount consideration of SPS in children, especially because the full spectrum of associated signs and symptoms continues to expand. Personal and family history of autoimmune diseases was common; hence, it is important for clinicians to be aware of common comorbid autoimmune conditions and monitor their development over time. Diagnostic evaluation can aid in making the diagnosis of SPS in children, as most individuals in our series had positive anti-GAD65 antibody titers in the setting of a classic clinical phenotype. Individuals received a combination of immunotherapy as well as symptomatic pharmacologic and non-pharmacologic therapy. Nearly all described physical limitations and were unable to carry out previous activities. In our cohort, compared with individuals with the classic phenotype, those with PERM phenotypically have different presentations because of brainstem involvement, cortical involvement, and likely overall more body regions involved. Clinical presentation along with particular examination findings may help distinguish these phenotypes. In addition, the time to diagnosis appears shorter and the mRS score slightly greater in individuals with PERM phenotype compared with those with classic phenotype. The main limitations of this study and others dealing with rare conditions are (1) small sample size, (2) lack of prognostic biomarkers of disease severity or progression, and (3) treatment approaches that are not uniform and often involve a multimodal approach, leading to difficulty in understanding effects of individual treatments. Future collaborative studies will help to minimize these limitations and further our understanding of pathophysiology, optimal evaluation and management, and outcomes in this potentially debilitating disease." The author concluded, "This study describes our center's experience with pediatric onset SPS with the goal of increasing provider awareness of this debilitating but treatable disease. Collaborative studies in the future would help to further our understanding of the pathophysiology, ideal approach for the evaluation and management, and outcomes of this potentially debilitating disease." This is 1 of the 2 valid cases reported in the same literature article.; Sender's Comments:  US-GLAXOSMITHKLINE-US2021GSK006919:same reporter