A 35 year old woman with a history of type 1 diabetes mellitus and anxiety is referred to you because of a "Frankenstein gait." When she enters your office, you note an awkward wide-based unsteady gait with a tendency to fall in a fashion like a log tumbling down. She also has pronounced lumbar lordosis. On exam, she has extreme truncal stiffness and generalized rigidity. When you palpate her lumbar, trunk, and proximal limb muscles, you find sustained muscular contractions of both agonist and antagonist muscles. She says the symptoms initially started in the low back and came on gradually, eventually involving the proximal limbs. When her walk started changing, she developed a lot of anxiety about going outside and being in public. Now, activities of daily living are becoming challenging.
In addition, she gets muscle spasms that seem triggered by sudden movement, noise, or emotional upset. These spasms begin in the truncal muscles and spread to the extremities. She has one in your office and you note the muscles becoming tight and rock-hard. Palpating it is like palpating a board. The rest of your motor and sensory exam is normal.
Challenge: What's your diagnosis?